B

Design And Development of Alfuzosin HCl
Floating Microspheres

An Introduction to Dissertation Submitted to
GUJARAT TECHNOLOGICAL UNIVERSITY, AHMEDABAD
In Partial Fulfillment of the Requirement for the Degree of

MASTER OF PHARMACY
IN
PHARMACEUTICS
DECEMBER 2012

Research Guide Student

Dr. M.R.Patel (M. Pharm, Ph.D) Ms. Shah Megha A (B. Pharm))
Associate Professor M.pharm, Department of Pharmaceutics
H.O.D., Department of Pharmaceutics, Enrollment No:-112520808007
Shri B.M.Shah College of Pharmaceutical Shri B.M.Shah College of
Education and Research, Pharmaceutical Education and Research
Modasa, Gujarat Modasa, Gujarat.

DEPARTMENT OF PHARMACEUTICS
Shri B. M. Shah College Of Pharmaceutical
Education & Research,
Modasa, GUJARAT,INDIA

CERTIFICATE
This is to certify that the Synopsis to the dissertation entitled “Design
and Development of Alfuzosin HCl Floating Microspheres” is a
bonafide work done by Ms. Shah Megha A, Enrollment No:
112520808007, in partial fulfillment of the requirement for the degree of
Master of Pharmacy. I further certify that the Research/Literature work
was carried out under my supervision and guidance at Department of
Pharmaceutics and Pharmaceutical Technology, Shri B.M.Shah College
of Pharmaceutical Education and Research, Modasa, Gujarat, during the
academic year 2012- 2013, Semester- III.

Research Guide:

DR. M.R.Patel (M.Pharm, Ph.D.)
H.O.D.,Deaprtmaent of Pharmaceutics,
Shri B.M.Shah College of Pharmaceutical Education and Research,
Modasa – 383315,
Gujarat, India.

Forwarded by:

DR. N.M.Patel (M. Pharm., Ph.D.)
Principal
Shri B.M.Shah College of Pharmaceutical Education and Research,
Modasa – 383315,
Gujarat,
India

INDEX

SR PAGE
NO. CONTENTS NO.
1 AIM OF RESEARCH WORK 1

2 INTRODUCTION TO DOSAGE FORM 3

3 INTRODUCTION TO DRUG 19

4 LITERATURE REVIEW OF DOSAGE FORM 24

5 LITERATURE REVIEW OF DRUG 28

6 LIST OF MATERIALS AND EQUIPMENTS 29

7 FUTURE PLAN OF RESEARCH WORK 31

8 REFERENCES 32

B.M.C.P.E.R.MODASA Introduction to Dissertation

1. AIM OF RESEARCH WORK
1.1 Aim of Present Work:
AlfuzosinHClis an alpha-adrenergic blocker used to treat benign prostatic hyperplasia
(BPH). It works by relaxing the muscles in the prostate and bladder neck, making it
easier to urinate. The recommended dose of alfuzosin is 2.5mg in three divided dose per
day. It is generally given in 10 mg/day to 30mg/day. The biological half life of Alfuzosin
Hydrochloride is 10 hours. The bioavailability of Alfuzosin hydrochloride is only 49 %1.

Sustained drug delivery of Alfuzosin HCl can be given orally due to its absorption is
through gastrointestinal tract. But maximum absorption site of drug is in proximal part of
small intestine. So, most of the drug is absorbed in stomach and after that in colon there
is decrease in absorption occurs.

Administration of conventional tablet of Alfuzosin Hydrochloride has been reported to
exhibit fluctuation in plasma drug concentration which results in manifestation of side
effects or reduction in drug concentration at absorption site. But In Benign prostate
hyperplasia there is release of drug in sustained manner and also requires Steady state
plasma concentration. So, formulation of floating drug delivery satisfies these conditions.
Gastro retentive drug delivery system can be retained in stomach for prolonged time and
assist in increasing sustained delivery of drug that have narrow absorption window. There
are so many approaches offloating drug delivery like Hydro dynamically balanced
system, Gas generating system, Raft forming system, Low density system, High density
system and Bioadhesive system2.

Hence objective of study to formulate floating microspheres of Alfuzosin Hydrochloride
to improve bioavailability and also get steady state plasma concentration.

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1.2 RATIONALE:

 Alfuzosin HCl is used in benign prostatic hyperplasia (BPH) and also used as
Anti hypertensive agent.
 It is class 1 drug so rapidly absorbed after oral administration. Hence to reduce
solubility and controlled release formulation.
 Alfuzosin HClhas bio-availability is only 49%. Andshort biological half life is 10
hours.
 In BPH there is need of steady state plasma concentration throughout treatment.
Alfuzosin have Narrow absorption window in proximal part of small intestine.
 In turn there is increase in bioavailability of alfuzosin HCl so reduce Dosing
frequency of drug and also achieve release of drug in controlled manner with
steady state plasma concentration.
 Reduce dosing frequency and improve surface area to volume ratio by using
floating microspheres.

1.3 OBJECTIVE:
 The aim of this research was to develop and optimize gastroretentive
microspheres of Alfuzosin HCl.
 Screening of the polymers for total and proportional amount for desired drug
release.
 Study the effect of different fillers on the release of the drug.
 Optimization of drug to polymer ratio and polymer to polymer ratio.
 To check compatibility of drug and excipients.
 Optimize the formulation using a suitable experimental design.

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2. INTRODUCTION TO DOSAGE FORM
Historically, the oral delivery of drugs is by far themost preferable route of drug delivery
due to the easeof administration, patient compliance and flexibility informulation, etc.
From immediate release to site-specific delivery, oral dosage forms have
reallyprogressed. However, it is a well-accepted fact that itis difficult to predict the real in
vivo time of releasewith solid, oral controlled release dosage forms. Thus,drug absorption
in the gastrointestinal (GI) tract maybe very less in terms of percentage drug absorbed
and highly variable in certain circumstances 2
Drug Delivery system is becomingincreasingly sophisticated as pharmaceutical
scientistsacquire a better understanding of the physicochemicaland biological parameters
pertinent to theirperformances. Controlled Drug Delivery Systemprovides drug release at
a predetermined, predictableand controlled rate to achieve high therapeuticefficiency with
minimal toxicity.
Despite tremendousadvancement in drug delivery, oral route remains thepreferred route
for the administration of therapeuticagents and oral drug delivery is by far the
mostpreferable route of drug delivery because of low costof therapy and ease of
administration leads to highlevels of patient compliance as well as the fact
thatgastrointestinal physiology offers more flexibility indosage form design than most
other routes,consequently much effort has been put intodevelopment of strategies that
could improve patientcompliance through oral route.3
Gastric emptying of dosage forms is anextremely variable process and ability to prolong
andcontrol emptying time is a valuable asset for dosageforms, which reside in the
stomach for a longer periodof time than conventional dosage forms. Severaldifficulties
are faced in designing controlled releasesystems for better absorption and
enhancedbioavailability. One of such difficulties is the inabilityto confine the dosage
form in the desired area of thegastrointestinal tract. Drug absorption from
thegastrointestinal tract is a complex procedure and issubject to many variables. It is
widely acknowledgedthat the extent of gastrointestinal tract drug absorptionis related to
contact time with the small intestinalmucosa. Thus small transit time is an
[3]
importantparameter for drugs that are incompletely absorbed The controlled gastric
retention of solid dosage formsmay be achieved by the mechanisms of

Megha A Shah 3


mucoadhesion,flotation, sedimentation, expansion modified shapesystems or by the
simultaneous administration ofpharmacological agent that delay gastric emptying.This
review focuses on the principal mechanism offloatation to achieve gastric retention.
Current Approaches toGastroretentive Drug Delivery System 8
A. Floating drug delivery systems (FDDS): Floating FDDS is aneffective technology to
prolong the gastric residence time in order toimprove the bioavailability of the drug.
FDDS are low-densitysystems that have sufficient buoyancy to float over the
gastriccontents and remain in the stomach for a prolonged period. Floatingsystems can be
classified as effervescent and no effervescentsystem.
I) Effervescent systems
These buoyant delivery systems utilize matrices prepared withswellable polymers such as
Methocel or polysaccharides, e.g.,chitosan, and effervescent components, e.g., sodium
bicarbonate andcitric or tartaric acid or matrices containing chambers of liquid thatgasify
at body temperature.Gas can be introduced into the floating chamber by the
volatilizationof an organic solvent (e.g., ether or cyclopentane) or by the carbondioxide
produced as a result of an effervescent reaction betweenorganic acids and carbonate–
bicarbonate salts .Thematrices are fabricated so that upon arrival in the stomach,
carbondioxide is liberated by the acidity of the gastric contents and isentrapped in the
gellified hydrocolloid. This produces an upwardmotion of he dosage form and maintains
its buoyancy.
II) Noneffervescent systems
Noneffervescent systems incorporate a high level (20–75% w/w) ofone or more gel-
forming, highly swellable, cellulosic hydrocolloids(e.g., hydroxylethylcellulose,
hydroxypropylcellulose,hydroxylpropylmethylcellulose[HPMC],a carboxymethyl
cellulose), polysaccharides,ormatrix-formingpolymers(e.g., polycarbophil, polyacrylates,
and polystyrene) intotablets or capsules9. Upon coming into contact with gastric fluid,
these gel formers, polysaccharides, and polymers hydrate and form a colloidal gel barrier
that controls the rate of fluid penetration into th device and consequent drug release10-11.
The air trapped by theswollen polymer lowers the density of and confers buoyancy to the
dosage form.

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B) Bio Mucoadhesive systems
Bio Mucoadhesive systems bind to the gastric epithelial cell surface, ormucin, and
increase the GRT by increasing the intimacy andduration of contact between the dosage
form and the biologicalmembrane. The adherence of the delivery system to the gastric
wall increases residence time at a particular site, thereby improvingbioavailability12. A
bio mucoadhesive substance is a natural orsynthetic polymer capable of adhering to a
biological membrane or the mucus lining of the GIT (mucoadhesive polymer). On the
basis of binding of polymers to the mucin-epithelial surface can be subdivided into two
broad categories.
a. Hydration-mediated adhesion
Certain hydrophilic polymers tend to imbibe large amount of waterand become sticky,
thereby acquiring bioadhesive properties.
b. Bonding-mediated adhesion
mechanical bonding and chemical bonding. Chemical bonds may be either covalent
(primary) or ionic (secondary) in nature. Secondarychemical bonds consist of dispersive
interactions (i.e., Vander Waalsinteractions) and stronger specific interactions such as
hydrogen bonds. The hydrophilic functional groups responsible for forming hydrogen
bonds are the hydroxyl and carboxylic groups.
C) Receptor-mediated adhesion
Certain polymers can bind to specific receptor sites on the surface of cells, thereby
enhancing the gastric retention of dosage forms.Certain plant lectins such as tomato
lectins interact specifically withthe sugar groups present in mucus or on the glycocalyx.
D) Expandable, unfoldable and swellable Systems
Gastroretentivity of a pharmaceutical dosage form can be enhancedby increasing its size
above the diameter of the pylorus ifthe dosage form can attain the larger size than
pylorus, thegastroretentivity of that dosage form will be possible for long time.This large
size should be achieved fairly quickly; otherwise dosageform will be emptied through the
pylorus. Thus, configurationsrequired to develop an expandable system to prolong GRT
are:
I. A small configuration for oral intake,
II. An expanded gastroretentive form, and

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III. A final small form enabling evacuation following drug release from the device.
In addition they should be able enough to withstand peristalsis andmechanical
contractility of the stomach14.However, owing to significant individual variation, the
cut-off size cannot be determined exactly. Unfoldable systems are available invarious
shapes as shown in figure-4.The concept is to make a carrier, such as a capsule, which
extends in the stomach. Caldwell et al, proposed different geometric forms like
tetrahedron15, ring or planar membrane (4-lobed, disc or 4-limbed cross form) of
bioerodiblepolymer compressed within a capsule.
E) High-density systems
Gastric contents have a density close to water (¨1.004 g/cm3). When high density pellets
is given to the patient, it will sink to the bottomof the stomach and are entrapped in the
folds of the antrumand withstand the peristaltic waves of the stomach wall17.
Sedimentation has been employed as a retention mechanism for high densitysystems. A
density ~3g/cm3 seems necessary for significant
Factors Affecting Gastric Retention:
Gastric residence time of anoral dosage form is affected by several factors. To pass
through thepyloric valve into the small intestine the particle size should be inthe range of
1 to 2 mm6. The rate of gastric emptying and gastricretention of GRFDDS depends
mainly on-
A) Meals: The rate of gastric emptying depends mainly on nature ofmeal and caloric
content of meals.
 Nature of meal: Feeding of indigestible polymers or fatty acid saltscan change
the motility pattern of the stomach to a fed state, thusdecreasing the gastric
emptying rate and prolonging drug release.
 Caloric content of meal: GRT can be increased by four to 10 hourswith a meal
that is high in proteins and fats
B) Volume of GI fluid: The resting volume of the stomach is 25 to50 ml. When volume
is large, the emptying is faster. Fluids taken atbody temperature leave the stomach faster
than colder or warmerfluids.

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C) Dosage form related factors
 Density: A buoyant dosage form having a density of less than that of the gastric
fluids floats. Since it is away from the pyloricsphincter, the dosage unit is retained
in the stomach for a prolonged period.
 Size: Dosage form units with a diameter of more than 7.5mm are reported to have
an increase GRT compared with those with a diameter of 9.9mm. Small-size
tablets leave the stomach during the housekeeping waves.
 Shape of dosage form: Tetrahedron and ringshaped deviceswith a flexural
modulus of 48 and 22.5 kilopounds per squareinch (KSI) are reported to have
better GRT ≈90% to 100%retention at 24 hours compared with other shapes.
 Single or multiple unit formulation: Multiple unit formulationsshow a more
predictable release profile and insignificantimpairing of performance due to
failure of units, allow co-administration of units with different release profiles or
containing incompatible substances and permit a larger margin ofsafety against
dosage form failure compared with single unitdosage forms.
D) Fed Conditions
 Fed or unfed state: Under fasting conditions, the GI motility ischaracterised by
periods of strong motor activity or the migratingmyoelectric complex (MMC) that
occurs every 1.5 to 2 hours.However, in the fed state, MMC is delayed and GRT
isconsiderably longer.
 Frequency of feed: The GRT can increase by over 400 minutes when successive
meals are given compared with a single meal.due to the low frequency of MMC.
E) Patient related factors
 Gender: Mean ambulatory GRT in males (3.4±0.6 hours) is lesscompared with
their age and racematched female counterparts(4.6±1.2 hours), regardless of the
weight, height and bodysurface.
 Age: Elderly people, especially those over 70, have asignificantly longer GRT.
 Posture: GRT can vary between supine and upright ambulatorystates of
thepatient.
 Concomitant drug administration: Anticholinergics likeatropine and
propantheline, opiates like codeine and prokinetic agents like metoclopramide

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ADVANTAGES OF FLOATING DRUG DELIVERYSYSTEMS 9
 The following advantages of the floating drug deliverysystems
 The gastroretensive systems are advantageous for drugsabsorbed through the
stomach. E.g. Ferrous salts, antacids.
 Acidic substances like aspirin cause irritation on thestomach wall when come in
contact with it. Hence HBSformulation may be useful for the administration of
aspirinand other similar drugs.
 Administration of prolongs release floating dosage forms,tablet or capsules, will
result in dissolution of the drug in thegastric fluid. They dissolve in the gastric
fluid would beavailable for absorption in the small intestine after emptyingof the
stomach contents. It is therefore expected that a drugwill be fully absorbed from
floating dosage forms if itremains in the solution form even at the alkaline pH of
theintestine.
 The gastroretensive systems are advantageous for drugsmeant for local action in
the stomach. E.g. antacids.
 When there is a vigorous intestinal movement and a shorttransit time as might
occur in certain type of diarrhoea, poorabsorption is expected. Under such
circumstances it may beadvantageous to keep the drug in floating condition
instomach to get a relatively better response
2.1 FLOATING MICROSPHERES 10:
Novel drug delivery system aims to deliver the drug at a rate directed by the needs of the
body during the period of treatment, and channel the active entity to the site of action. At
present, no available drug delivery system behaves ideally achieving all the lofty goals,
but sincere attempts have been made to achieve them through novel approaches in drug
delivery. A number of novel drug delivery systems have emerged encompassing various
routes of administration, to achieve controlled and targeted drug delivery.1 Currently,
microencapsulation techniques are most widely used in the development and production
of improved drug- and food-delivery systems. These techniques frequently result in
products containing numerous variably coated particles. Microspheres of biodegradable
and nonbiodegradable polymers have been investigated for sustained release depending
upon the final application. Microsphere based drug delivery system has received

Megha A Shah 8


considerable attention in recent years. The most important characteristic of microspheres
is the microphase separation morphology which endows it with a controlled variability in
degradation rate and also drug release.
A) CLASSIFICATION:
Microparticle

Microcapsule Microsphere

Monocore Polycore Matrix Reservoir

Generally, the micro particulate delivery systems are intended for oral and topical use.
The particles can be embedded within a polymeric or proteinic matrix network in either
as solid aggregated state or a molecular dispersion, resulting in the formulation of
microspheres. Alternatively, the particles can be coated by a solidified polymeric or
proteinic envelope, leading to the formation of microcapsules.
The ultimate objective of micro particulate-delivery systems is to control and extend the
release of the active ingredient from the coated particle without attempting to modify the
normal bio fate of the active molecules in the body after administration and absorption.
The organ distribution and elimination of these molecules will not be modified and will
depend only on their physicochemical properties. Thus, the principle of drug targeting is
to reduce the total amout of drug administered, and the cost of therapy while optimizing
its activity.
B) ADVANTAGES:
Sustained delivery: By encapsulating a drug in a polymer matrix, which limits access of the
biological fluid into the drug until the time of degradation, micro particles maintain the
bloodlevel of the drug within a therapeutic window for a prolonged period. Toxic side effects
can be minimized.

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Local delivery: Subcutaneously or intramuscularly applied microparticles can maintain a
therapeutically effective concentration at the site of action for a desirable duration. The local
delivery system obviates systemic drug administration for local therapeutic effects and can
reduce the related systemic side effects. This system has proven beneficial for delivery of
local anaesthetics.
Pulsatile delivery: While burst and pulsatile release is not considered desirable for the
sustained delivery application, this release pattern proves to be useful for delivery of
antibiotics and vaccines. Pulsatile release of antibiotics can alleviate evolution of the
bacterial resistance. In the vaccine delivery, initial burst followed by delayed release pulses
can mimic an initial and boost injection, respectively.
C) USES:
 Taste and odour masking
 Conversion of oil and other liquids, facilitating ease of handling.
 Protection of the drugs from the environment.
 Improvement of flow properties
 Safe handling of toxic substances
 Dispersion of water insoluble substances on aqueous media
 Production of sustained release, controlled release and targeted medications.
 Reduced dose dumping potential compared to large implantable devices
2. TYPES OF MICROSPHERE
 Magnetic microspheres
 Bioadhesive microspheres
 Floating microspheres
 Radioactive microspheres
Magnetic microspheres:
This kind of delivery system is very much important which localises the drug to the disease
Site. In this larger amount of freely circulating drug can be replaced by smaller amount of
magnetically targeted drug. Magnetic carriers receive magnetic responses to a magnetic field
from incorporated materials,
The different types are:
Therapeutic magnetic microspheres:They are used to deliver chemotherapeutic agent to
liver tumour. Proteins and peptides can also be targeted through this system.

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Diagnostic microspheres: These can be used for imaging liver metastases and also can be
used to distinguish bowel loops from other abdominal structures by forming nano size
particles supramagnetic iron oxides.
Bioadhesive microspheres:
Adhesion can be defined as sticking of drug to the membrane by using the sticking property
of the water soluble polymers. Adhesion of drug delivery device to the mucosal membrane
such as buccal, ocular, rectal, nasal, etc. can be termed as bioadhesion. These kinds of
microspheres exhibit a prolonged residence time at the site of application and causes intimate
contact with the absorption site and produces better therapeutic action.
Radioactive microspheres:
Radio emobilisation therapy microspheres sized from 10-30 nm which are larger than
capillaries and get tapped in first capillary bed when they come across. So they are injected to
the arteries that lead to tumour of interest. Hence radioactive microspheres deliver high
radiation dose to the targeted areas without damaging the normal surrounding tissues. It
differs from drug delivery systems, as radio activity is not released from microspheres but
acts from within a radioisotope-typical-distance and the different kinds of radioactive
microspheres are α emitters, β emitters and γ emitters.
Floating microspheres:
In floating types the bulk density is less than the gastric fluid so remains buoyant in stomach
without affected by gastric emptying. The drug is released slowly at the desired rate by
increasing gastric residence, if the system is floating on gastric content. Moreover it reduces
chances of striking, dose dumping and also it produces prolonged therapeutic effect, therefore
reduces dosing frequency.
3. METHODS OF PREPARATION OF MICROSPHERES (5)
Incorporation of solid, liquid or gases into one or more polymeric coatings can be done by
microencapsulation technique. The different methods used for various microspheres
preparation depends on particle size, route of administration, duration of drug release,
method of cross linking, evaporation time and co-precipitation, etc. The various methods of
Preparations are:
A. Emulsion Solvent Evaporation Technique
B. Emulsion Cross Linking Technique
C. Emulsion-Solvent Diffusion Technique

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D. Emulsification Heat Stabilizing Technique
E. Co-acervation Phase Separation Technique
a) Thermal Change
b) Non-Solvent Addition
c) Polymer Addition
d) Salt Addition
e) Polymer-Polymer Interaction
F. Spray Drying Technique
G. Polymerisation Technique
a) Normal polymerisation
b) Interfacial polymerisation
H. Ionic Gelation Technique
I. Hydroxyl Appetite (HAP) Microspheres In Sphere Morphology
J. Hot Melt Microencapsulation technique
A. Emulsion Solvent Evaporation Technique:
In this technique the drug is dissolved in polymer which is previously dissolved in
chloroform and the resulting solution is added drop wise to aqueous phase containing 0 .2 %
of PVP as emulsifying agent and agitated at 500 rpm, then the drug and polymer solution
Transformed into fine droplet which solidifies into rigid microspheres and then collected by
filtration,washed with demineralised water. Finally desiccated at room temperature for 24 hrs
B. Emulsion Cross Linking Technique
In this method, drug is dissolved in aqueous gelatine solution which is previously heated for
1 hr. at 40 ⁰C. The solution is added drop wise to liquid paraffin while stirring the mixture at
1500 rpm for 10 min at 35⁰C, which results in w/o emulsion further stirring is done for 10
min at 15⁰ C. Then the microspheres are washed with acetone and isopropyl alcohol. Further
air dried and dispersed in 5ml of aqueous glutaraldehyde saturated toluene solution at room
temperature for 3 hrs. for cross linking and treated with 100ml of 10Mm glycine solution
containing 0.1%w/v of tween 80 at 37 ⁰ C for 10 min to block unreacted glutaraldehyde.
C. Emulsion-Solvent Diffusion Technique
In order to improve the residence time in colon floating microparticles of drug is prepared
byemulsion solvent diffusion technique. The drug polymer mixture is dissolved in a mixture
of ethanol and dichloromethane (1:1) then the mixture is added drop wise to sodium lauryl

Megha A Shah 12


sulphate (SLS) solution. The solution is stirred with propeller type agitator at room
temperature at 150 rpm for 1 hr, washed and dried in a desiccator at room temperature.
D. Emulsification Heat Stabilizing Technique:
In this method, drug and polymer are dissolved in 20 ml of deionised water and 5 ml of egg
albumin solution and 0.1% of Tween‐80 are added stirred it for 30 min. The prepared
solution is used as aqueous phase. The oil phase is prepared by mixing 20 ml of sunflower oil
and 5ml of diethyl ether with 1% span‐80 (as emulsifier) and stirred it for 20 mins at
800‐1000 rpm on a magnetic stirrer. The primary emulsion is prepared by adding the oil
phase drop wise to the aqueous phase followed by stirring it for 30 mins at 800‐1000 rpm.
The prepared primary emulsion is added to pre‐heated (65 to 70⁰C) sunflower oil (80 ml) by
using 21 No. needle and stirred at 1000‐1200 rpm for 2 hrs till the solidification of
microspheres takes place. The suspension then allowed to cool to room temperature with
continuous stirring using a magnetic stirrer. On cooling, 100 ml of anhydrous ether is added.
The suspension containing the microspheres is centrifuged for 15 mins and the settled
microspheres are washed three times with ether to remove traces of oil on microspheres
surfaces. The obtained microspheres are then vacuum dried in a desiccator overnight and
stored at 4⁰C in dark.
E. Co-acervation Phase Separation Technique:
a)Thermal Change: Microspheres are formed by dissolving polymer (ethyl cellulose) in
cyclohexane with vigorous stirring at 80 ⁰C by heating. Then the drug is finely pulverized
and added to the above solution with vigorous stirring. The phase separation is brought about
by reducing temperature using ice bath. The product is washed twice with cyclohexane and
air dried then passed through sieve (sieve no. 40) to obtain individual microcapsule.
b) Non Solvent Addition: Microspheres are formed by dissolving polymer (ethyl cellulose)
in toluene containing propyl-isobutylene in a closed beaker with stirring for 6 hrs. at 500 rpm
and the drug is dispersed in it. Stirring is continued for 15 mins., then phase separation is
brought about by petroleum benzene with continuous stirring. The microcapsules washed
with n-hexane and air dried for 2 hrs., and kept in an oven at 50⁰C for 4 hrs.
c) Polymer Addition: Microspheres are formed by dissolving polymer (ethyl cellulose)
isdissolved in toluene, then1 part is added to 4 parts of crystalline methylene
bluehydrochloride. Co-acervation is accomplished by adding liquid polybuta-diene. Then the

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polymer coating is solidified by adding a nonsolvent (hexane). The resulting product is
washed and air dried.
d) Salt Addition: Microspheres are formed by dissolving oil soluble vitamin in corn oil and
is emulsified by using pig skin gelatin under condition of temperature 50⁰ C, coacervation is
induced by adding sodium sulphate. The resultant microspheres product is collected and
washed with water, chilled below gelation temperature of gelatin and dried by using spray
drying.
e) Polymer-Polymer Interaction: In this process, aqueous solution of gum Arabica and
gelatin (isoelectic point 8.9) are prepared, the homogeneous polymer solutions are mixed
together in equal amount, diluted to about twice their volume with water, adjusted to pH 4.5
and warmed to 40- 45⁰C. the oppositely charged macromolecules interact at these conditions
and undergo co-acervation. While maintaining the warm temperature, the liquid core material
(methyl salicylate) is added to polmer solution and stirred well. Then the mixture is cooled to
25⁰C and coating is rigidised by cooling the mixture to 10⁰C.
F. Spray Drying Technique
This method is used to prepare polymeric blended microspheres loaded with drug. It involves
dispersing the core material into liquefied coating material and then spraying the mixture in
the environment for solidification of coating followed by rapid evaporation of solvent.
Organic solution of poly epsilon-caprolactone (PCL) and cellulose acetate butyrate (CAB), in
different weight ratios with drug is prepared and sprayed in different experimental condition
achieving drug loaded microspheres. This is rapid but may loosecrystalinity due to fast
drying process.
G. Polymerization Techniques:
Mainly two techniques are used for the preparation of microsphere by polymerization
technique:
(a) Normal polymerization:
Normal polymerization classified as:
1. Bulk polymerization
2. Suspension/ pearl polymerization
3. Emulsion polymerization

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1. In bulk polymerization, a monomer or a mixture of monomers along with the initiator or
catalyst is usually heated to initiate polymerization. Polymer obtained may be moulded as
microspheres. Drug loading may be done by adding the drug during the process of
polymerization. It is a pure polymer formation technique but it is very difficult to dissipate
the heat of reaction which affects the thermo labile active ingredients.
2. Suspension polymerizationis carried out at lower temperature and also referred to as pearl
polymerization in which the monomer mixture is heated with active drug as droplets
dispersion in continuous aqueous phase. Microsphere size obtained by suspension techniques
is less the 100 μm.
3. Emulsion polymerization differs from the suspension polymerization due to presence of
initiator in aqueous phase and also carried out at low temperature as suspension. External
phase normally water in last two techniques so through which heat can be easily dissipated.
The formation of higher polymer at faster rate is possible by these techniques but sometimes
association of polymer with the unreacted monomer and other additives can occur.
(b) Interfacial polymerization
It involves the reaction of various monomers at the interface between the two immiscible
liquid phases to form a film of polymer that essentially envelops the dispersed phase. In this
technique two reacting monomers are employed; one is dissolved in continuous phase while
other is dispersed in continuous phase (aqueous in nature) throughout which the second
monomer is emulsified. Two conditions arise because of the solubility of formed polymer in
the emulsion droplet. The formation is Monolithic, if the polymer is soluble in droplet and the
formation is Capsular type if the polymer is insoluble in droplet.
H. Ionic Gelation Technique:
In this technique polymer is dissolved in purified water to form a homogeneous polymer
Solution. The core material (drug) as fine powder passed through mesh no.120 is added to the
polymer solution and mixed to form a smooth viscous dispersion. This dispersion is added
drop wise into 10%w/v CaCl2 solution through a syringe with a needle of diameter 0.55mm.
The added droplets are retained in CaCl2 solution and allowed to cure for 20 minutes at 200
rpm to produce spherical rigid microsphere. Finally the microspheres are collected and dried
in an oven at a temperature 45⁰C for 12 hrs
I. Hydroxyl Appetite (HAP) Microspheres in Sphere Morphology
In this method, initially HAP granules obtained by precipitation method followed by spray

Megha A Shah 15


drying process. Microspheres are prepared by oil-in-water emulsion followed by solvent
evaporation technique. Oil-in-water emulsion obtained by dispersing the organic phase
(dichloromethane solution containing 5% of EthyleneVinylAcetate and appropriate amount
of HAP) in the aqueous medium of the surfactant. While dispersing in aqueous phase, the
organic phase is transformed into tiny droplets and each droplet surrounded by surfactant
molecules. The protective layer thus formed on the surface which prevents the droplets from
coalescing and helps to stay individual droplets. While stirring, dichloromethane (DCM) is
slowly evaporated from the droplets and after the complete removal of DCM, the droplets
solidifies to become individual microspheres. The size of the droplets formed depends on
many factors like types and concentration of the stabilizing agents, type and speed of stirring
employed, etc, which in turn affects the size of the final microspheres formed.
J. Hot Melt Microencapsulation Technique
The polymer is first melted and then mixed with solid particles of the drug that has been
sieved to less than 50 μm. The mixture is suspended in a non-miscible solvent (like silicone
oil), continuously stirred, and heated to 5°C above the melting point of the polymer. Once the
emulsion is stabilized, it is cooled until the polymer particles solidify. The resulting
microspheres are washed by decantation with petroleum ether. The primary objective for
developing this method is to develop a microencapsulation process suitable for the water
labile polymers, e.g. polyanhydrides. Microspheres with diameter of 1-1000 μm can be
obtained and the size distribution can be easily controlled by altering the stirring rate. The
only disadvantage of this method is moderate temperature to which the drug is exposed.

EVALUATION OF FLOATING MICROSPHERES
2.1.1. Micro-meritic properties
Floating microspheres are characterized by their micromeritic properties such as angle of
repose, tapped density, compressibility index, true densityand flow properties. True density
is determined by liquid displacement method; tapped density and compressibility index
are calculated by measuring the change in volume using a bulk density apparatus; angle of
repose is determined by fixed funnel method. The hollow nature of microspheresis
confirmed by scanning electron microscopy. The compressibility index is calculated using
following formula:

I = Vb –Vt / Vb x 100

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Where, Vb is the bulk volume and Vt is the tapped volume.

The value given below 15% indicates a powder which usually give rise to good flow
characteristics, whereas above 25% indicate poor flow ability.

2.1.2. Particle size and shape
Scanning electron microscopy (SEM) provides higher resolution in contrast to the light
microscopy(LM). The most widely used procedures to visualize microparticles are
conventional light microscopy (LM) and scanning electron microscopy (SEM). Both can
be used to determine the shape and outer structure of multi particulate. LM provides a
control over coating parameters in case of double walled microspheres. The
multiparticulate structures can be visualized before and after coating and the change can
be measured microscopically. SEM allows investigations of the multiparticulate surfaces
and after particles are cross sectioned, it can also be used for the investigation of double
walled systems. Conflocal fluorescence microscopyis used for the structure
characterization of multiple walled microspheres. Laser light scattering and multi size
coulter counter are other than instrumental methods, which can be used for the
characterization of size, shape and morphology of the multi particulates.

2.1.3. Floating behavior
Appropriate quantity of the floating microparticulates is placed in 100 ml of the simulated
gastric fluid (SGF, pH 2.0), the mixture isstirred with a magnetic stirrer. The layer of
buoyantmicroparticulate is pipetted and separated by filtration. Particles in the sinking
particulate layer are separated by filtration. Particles of both types are dried in a
desiccator until constant weight is achieved. Both the fractions of microspheres are
weighed and buoyancy is determined by the weight ratio of floating particles to the sum of
floating and sinking particles.

Buoyancy (%) = Wf / Wf + Ws

Where, Wf and Ws are the weights of the floating and settled microparticles.

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2.1.4. Entrapment efficiency
The capture efficiency of the multi particulate or thepercent entrapment can be determined
by allowing washed multiparticulate to lyse. The lysate is then subjected to the
determination of active constituents as per monograph requirement. The percent
encapsulation efficiency is calculated using equation:

% Entrapment = Actual content/Theoretical content
x 100

2.1.5. In-vitro drug release studies
The release rate of floating microspheres is determined using United States
Pharmacopoeia (USP) XXIII basket type dissolution apparatus. A weighed amount of
floating microspheres equivalent to 50 mg drug is filled into a hard gelatin capsule (No. 0)
and placed in the basket of dissolution rate apparatus. 500 ml of the SGF containing
0.02% w/v of Tween 20 is used as the dissolution medium. The dissolution fluid is
maintained at 37 ± 1° at a rotation speed of 100 rpm. Perfect sink conditions prevailed
during the drug release study. 5ml samples are withdrawn at each 30 min interval, passed
through a 0.25 µm membrane filter (Millipore), and analyzed using LC/MS/MS method
to determine the concentration present in the dissolution medium. The initial volume of
the dissolution fluid is maintained by adding 5 ml of fresh dissolution fluid after each
withdrawal.
2.1.6. Fourier trans form –infrared spectroscopy: (FTIR)
FTIR is used to determine the degradation of the polymeric matrix of the carrier system,
and also interaction between drug and polymer system if present.

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3. INTRODUCTION TO DRUG (12-15):

3.1 CHARACTERIZATION:
Alfuzosin hydrochloride is an alpha-adrenergic blocker used to treat benign prostatic
hyperplasia (BPH). It works by relaxing the muscles in the prostate and bladder neck,
making it easier to urinate.
Structure of Alfuzosin HCl:

IUPAC Name: (R,S)-N-[3-[(4-amino-6,7-dimethoxy-2-quinazolinyl)
methylamino]propyl]tetrahydro-2furancarboxamide
hydrochloride.

Empirical formula : C19H27N5O4

Molecular weight: 425.9gm/mol

Melting point: 240°C

Solubility : freely soluble in water, sparingly soluble in alcohol, and
practically insoluble in dichloromethane.

Category : Antihypertensive Agents
Adrenergic alpha-Antagonists

Storage : Preserve in tight containers. Protect from light and
humidity. And store at room temerature.

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3.2 CLINICAL PHARMACOLOGY :
3.2.1 Mechanism of action:
Alfuzosin is a non-subtype specific alpha(1)-adrenergic blocking agent that exhibits
selectivity for alpha(1)-adrenergic receptors in the lower urinary tract. Inhibition of these
adrenoreceptors leads to the relaxation of smooth muscle in the bladder neck and
prostate, resulting in the improvement in urine flow and a reduction in symptoms in
benign prostate hyperplasia. Alfuzosin also inhibits the vasoconstrictor effect of
circulating and locally released catecholamines (epinephrine and norepinephrine),
resulting in peripheral vasodilation.
3.2.2 Pharmacodynamics:
Alfuzosin is a quinazoline-derivative alpha-adrenergic blocking agent used to treat
hypertension and benign prostatic hyperplasia. Accordingly, alfuzosin is a selective
inhibitor of the alpha(1) subtype of alpha adrenergic receptors. In the human prostate,
alfuzosin antagonizes phenylephrine (alpha(1) agonist)-induced contractions, in vitro, and
binds with high affinity to the alpha1a adrenoceptor, which is thought to be the
predominant functional type in the prostate. Studies in normal human subjects have
shown that alfuzosin competitively antagonized the pressor effects of phenylephrine (an
alpha(1) agonist) and the systolic pressor effect of norepinephrine. The antihypertensive
effect of alfuzosin results from a decrease in systemic vascular resistance and the parent
compound alfuzosin is primarily responsible for the antihypertensive activity.
3.2.3 Pharmacokinetics:
Absorption: AlfuzosinHCl is rapidly absorbed and quick on set of action. Absorption is
50% lower under fasting conditions.
Distribution: AlfuzosinHCl has protein binding 82-90%; volume of distibution is 3.2
L/kg.
Metabolism:
Hepatic.Alfuzosin undergoes extensive metabolism by the liver, with only 11% of the
administered dose excreted unchanged in the urine. Alfuzosin is metabolized by three
metabolic pathways: oxidation, O-demethylations, and N-dealkylation. The metabolites
are not pharmacologically active. CYP3A4 is the principal hepatic enzyme isoform
involved in its metabolism.

Megha A Shah 20


Elimination half life : 10 hours

3.3 SIDE EFFECTS:
Nervous system
Nervous system side effects are among the most commonly reported and include
dizziness (5.7%), headache (3%) and fatigue (2.7%).
Respiratory
Respiratory side effects have included upper respiratory tract infection (3%), bronchitis,
sinusitis and pharyngitis.
Cardiovascular
Cardiovascular side effects reported possibly due to orthostasis have included dizziness
(5.7%), hypotension or postural hypotension (0.4%) and syncope (0.2 %). In addition,
tachycardia, chest pain, and angina pectoris in patients with preexisting coronary artery
disease have been reported in post marketing experience.
Other
Other side effects have included pain and rash. In addition, flushing, edema, angioedema,
pruritus, and rhinitis have been reported in postmarketing experience.
Gastrointestinal
Gastrointestinal side effects have included abdominal pain, dyspepsia, constipation and
nausea. Diarrhea has been reported in postmarketing experience.
Genitourinary
Genitourinary effects have included impotence and priapism.
Ocular
Ocular side effects including Intraoperative Floppy Iris Syndrome (IFIS) have been
observed in some patients undergoing phacoemulsification cataract surgery while being
treated with alpha-1 blockers.

Megha A Shah 21


3.4 PRECAUTIONS :

Before taking Alfuzosin hydrochloride, Apollo research medical teams if you are
allergic to it; or to other alpha blockers such as doxazosin, prazosin, terazosin; or
if you have any other allergies. This product may contain inactive ingredients,
which can cause allergic reactions or other problems. Talk to your pharmacist for
more details.
Before using this medication, tell your doctor or pharmacist your medical history,
especially of: other prostate gland problems (e.g., prostate cancer), heart problems
(e.g., angina, low blood pressure), kidney disease.
Alfuzosinhydrochloride, may cause a condition that affects the heart rhythm (QT
prolongation). QT prolongation can infrequently result in serious (rarely fatal)
fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting)
that require immediate medical attention. The risk of QT prolongation may be
increased if you have certain medical conditions or are taking other drugs that
may affect the heart rhythm.
Before using Alfuzosin hydrochloride,, tell your doctor or pharmacist if you have
any of the following conditions: certain heart problems (heart failure, slow
heartbeat, QT prolongation in the EKG), family history of certain heart problems
(QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk
of QT prolongation. This risk may increase if you use certain drugs (such as
diuretics/"water pills") or if you have conditions such as severe sweating,
diarrhea, or vomiting. Talk to your doctor about using Alfuzosin hydrochloride,
safely.

Megha A Shah 22


3.5 MARKETED FORMULATION:

Brand Name Composition Company

AFDURA tab Alfuzosinhcl 10mg SUN PHARMA

ALFOO tab Alfuzosinhcl 10mg DR. REDDY'S LAB

ALFUSIN tab Alfuzosinhcl 10mg CIPLA

ALFUSIN D tab Alfuzosinhcl 10mg, CIPLA
dutasteride 0.5mg

FLOTRAL tab Alfuzosinhcl 10mg RANBAXY

FUAL tab Alfuzosinhcl 10mg ALKEM

FULFLO tab Alfuzosinhcl 10mg ALEMBIC

XEFLO tab Alfuzosinhcl 10mg SUN

Megha A Shah 23


4. INTRODUCTION TO DOSAGE FORM:

EUDRAGITS100
Commercial form
EUDRAGIT® S 100 is Methacrylic Acid - Methyl Methacrylate Copolymer and
preferably used as a sustained release polymer.
Chemical structure
EUDRAGIT® S 100 is an anionic copolymer based on methacrylic acid and methyl
methacrylate. The ratio of the free carboxyl groups to the ester groups is approx. 1:2.

Characters
Description
Solid substances. White powders with a faint characteristic odour

Solubility
1 g of EUDRAGIT® S 100 dissolves in 7 g methanol, ethanol, in aqueous isopropyl
alcohol and acetone (containing approx. 3 % water), as well as in 1 N sodium
hydroxide to give clear to slightly cloudy solutions. EUDRAGIT S 100 is practically
insoluble in ethyl acetate, methylene chloride, petroleum ether and water.
Molecular weight is approx. 135,000.

Particle size
At least 95 % less than 0.25 mm. The particle size is determined according to Ph. Eur.
2.1.4 or USP <811>.
Film formation
When the Test solution is poured onto a glass plate, a clear film forms upon
evaporation of the solvent.
Storage
Protect from warm temperatures (USP, General
Notices). Protect against moisture.

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Viscosity / Apparent viscosity

EUDRAGIT® S 100: 50 - 200 mPa. The viscosity of the Test solution is determined
by means of a Brookfield viscometer (spindle 1 / 30 rpm / 20 °C).
EUDRAGIT® S 100: 22 - 52 mm2 / s according to JPE.

Density:- 0.831 - 0.852 g/cm3.

Identity testing
First identification
The material must comply with the tests for "Assay" and "Viscosity / Apparent
viscosity."
Second identification
IR spectroscopy on a dry film approx. 15 µm thick. To obtain the film, a few drops
of the Test solution are placed on a crystal disc (KBr, NaCl) and dried in vacuo
for about 2 hours at 70 °C. The figure shows the characteristic bands of the C=O
vibrations of the carboxylic acid groups at 1,705 cm-1 and of the esterified
carboxyl groups at 1,730 cm-1, as well as further ester vibrations at 1,150 - 1,160,
1,190 - 1,195 and 1,250 - 1,275 cm-1. The wide absorption range of the associated
OH groups between 2,500 and 3,500 cm-1 is superimposed by CHX vibrations at
2,900 - 3,000 cm-1. Further CHX vibrations can be discerned at 1,385 - 1,390, 1,450
and 1,485 cm-1.

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Hypromellose
Nonproprietary Names
BP: Hypromellose
JP: Hydroxypropylmethylcellulose
PhEur: Hypromellosum
Synonyms
Benecel MHPC; E464; hydroxypropyl methylcellulose; HPMC; Methocel;
methylcellulose propylene glycol ether; methyl hydroxypropylcellulose; Metolose;
Chemical Name and CAS Registry Number
Cellulose hydroxypropyl methyl ether [9004-65-3]
Empirical Formula and Molecular Weight
The PhEur 2005 describes hypromellose as a partly O-methylated and O-(2- hydroxyl
propylated) cellulose. It is available in several grades that vary in viscosity and extent of
substitution. Grades may be distinguished by appending a number indicative of the
apparent viscosity, in mPa s, of a 2% w/w aqueous solution at 20°C. Hypromellose
defined in the USP 28 specifies the substitution type by appending a four-digit number to
the non proprietary name: e.g., hypromellose 1828. The first two digits refer to the
approximate percentage content of the methoxy group (OCH3). The second two digits
refer to the approximate percentage content of the hydroxypropoxy group
(OCH2CH(OH)CH3),calculated on a dried basis. It contains methoxy and
hydroxypropoxy group. Molecular weight is approximately 10 000–1 500 000. The JP
2001 includes three separate monographs for hypromellose: hydroxyl propylmethyl
cellulose 2208, 2906, and 2910, respectively.
Structural Formula

where R is H, CH3, or CH3CH(OH)CH2

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Functional Category
Coating agent; film-former; rate-controlling polymer for sustained release; stabilizing
agent;suspending agent; tablet binder; viscosity-increasing agent.
Applications in Pharmaceutical Formulation or Technology
Hypromellose is widely used in oral, ophthalmic and topical pharmaceutical
formulations.
In oral products, hypromellose is primarily used as a tablet binder,1 in film-coating,2–7
and as a matrix for use in extended-release tablet formulations.8–12 Concentrations
between 2% and 5% w/w may be used as a binder in either wet- or dry-granulation
processes. High-viscosity grades may be used to retard the release of drugs from a matrix
at levels of 10–80% w/w in tablets and capsules.
Depending upon the viscosity grade, concentrations of 2–20% w/w are used for film-
forming solutions to film-coat tablets. Lower-viscosity grades are used in aqueous film-
coating solutions, while higher-viscosity grades are used with organic solvents. Examples
of film coating materials that are commercially available include AnyCoat C, Spectracel,
and Pharmacoat.
Hypromellose is also used as a suspending and thickening agent in topical formulations.
Compared with methylcellulose, hypromellose produces aqueous solutions of greater
clarity, with fewer undispersed fibers present, and is therefore preferred in formulations
for ophthalmic use. Hypromellose at concentrations between 0.45–1.0% w/w may be
added as a thickening agent to vehicles for eye drops and artificial tear solutions.
Hypromellose is also used as an emulsifier, suspending agent, and stabilizing agent in
topical gels and ointments. As a protective colloid, it can prevent droplets and particles
from coalescing or agglomerating, thus inhibiting the formation of sediments.
In addition, hypromellose is used in the manufacture of capsules, as an adhesive in plastic
bandages, and as a wetting agent for hard contact lenses. It is also widely used in
cosmetics and food products.
8. Description
Hypromellose is an odorless and tasteless, white or creamy-white fibrous or granular
powder.

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9. Typical Properties
Acidity/alkalinity:
 pH = 5.5–8.0 for a 1% w/w aqueous solution.
Ash:
 1.5–3.0%, depending upon the grade and viscosity.
Autoignition temperature:
 360°C
Melting point:
browns at 190–200°C; chars at 225–230°C. Glass transition temperature is 170–180°C.
Moisture content
hypromellose absorbs moisture from the atmosphere; the amount of water absorbed
depends upon the initial moisture content and the temperature and relative humidity of
the surrounding air
Solubility:
soluble in cold water, forming a viscous colloidal solution; practically insoluble in
chloroform, ethanol (95%), and ether, but soluble in mixtures of ethanol and
dichloromethane, mixtures of methanol and dichloromethane, and mixtures of water and
alcohol. Certain grades of hypromellose are soluble in aqueous acetone solutions,
mixtures of dichloromethane and propan-2-ol, and other organic solvents.
Viscosity (dynamic):
A wide range of viscosity types are commercially available. Aqueous solutions are most
commonly prepared, although hypromellose may also be dissolved in aqueous alcohols
such as ethanol and propan-2-ol provided the alcohol content is less than 50% w/w.
Dichloromethane and ethanol mixtures may also be used to prepare viscous hypromellose
solutions. Solutions prepared using organic solvents tend to be more viscous; increasing
concentration also produces more viscous solutions.
To prepare an aqueous solution, it is recommended that hypromellose is dispersed and
thoroughly hydrated in about 20–30% of the required amount of water. The water should
be vigorously stirred and heated to 80–90°C, then the remaining hypromellose should be
added.Sufficient cold water should then be added to produce the required volume.

Megha A Shah 28


When a water-miscible organic solvent such as ethanol (95%), glycol, or mixtures of
ethanol and dichloromethane are used, the hypromellose should first be dispersed into the
organic solvent, at a ratio of 5–8 parts of solvent to 1 part of hypromellose. Cold water is
then added to produce the required volume.
Typical viscosity values for 2% (w/v) aqueous solutions of Methocel (Dow Chemical
Co.). Viscosities measured at 20°C
Methocel product Nominal viscosity (mPa s)
Methocel K100 Premium 100
LVEP
Methocel K4M Premium 4000
Methocel K15M Premium 15 000
Methocel K100M Premium 100 000
Methocel E4M Premium 4000
Methocel F50 Premium 50
Methocel E10M Premium CR 10 000
Methocel E3 Premium LV 3
Metolose 60SH 50, 4000, 10 000
Metolose 65SH 50, 400, 1500, 4000
Metolose 90SH 100, 400, 4000, 15 000

10. Stability and Storage Conditions
Hypromellose powder is a stable material, although it is hygroscopic after drying.
Solutions are stable at pH 3–11. Increasing temperature reduces the viscosity of solutions.
Hypromellose undergoes a reversible sol–gel transformation upon heating and cooling,
respectively. The gel point is 50–90°C, depending upon the grade and concentration of
material.

Megha A Shah 29


Aqueous solutions are comparatively enzyme-resistant, providing good viscosity stability
during long-term storage. However, aqueous solutions are liable to microbial spoilage
and should be preserved with an antimicrobial preservative: when hypromellose is used
as a viscosity-increasing agent in ophthalmic solutions, benzalkonium chloride is
commonly used as the preservative. Aqueous solutions may also be sterilized by
autoclaving; the coagulated polymer must be redispersed on cooling by shaking.
Hypromellose powder should be stored in a well-closed container, in a cool, dry place.
11. Incompatibilities
Hypromellose is incompatible with some oxidizing agents. Since it is nonionic,
hypromellose will not complex with metallic salts or ionic organics to form insoluble
precipitates.
12. Method of Manufacture
A purified form of cellulose, obtained from cotton linters or wood pulp, is reacted with
sodium hydroxide solution to produce a swollen alkali cellulose that is chemically more
reactive than untreated cellulose. The alkali cellulose is then treated with chloromethane
and propylene oxide to produce methyl hydroxypropyl ethers of cellulose. The fibrous
reaction product is then purified and ground to a fine, uniform powder or granules.
13. Safety
Hypromellose is widely used as an excipient in oral and topical pharmaceutical
formulations.
It is also used extensively in cosmetics and food products.
Hypromellose is generally regarded as a nontoxic and nonirritant material, although
excessive oral consumption may have a laxative effect. The WHO has not specified an
acceptable daily intake for hypromellose since the levels consumed were not considered
to represent a hazard to health.
LD50 (mouse, IP): 5 g/kg
LD50 (rat, IP): 5.2 g/kg
14. Handling Precautions
Observe normal precautions appropriate to the circumstances and quantity of material
handled. Hypromellose dust may be irritant to the eyes and eye protection is

Megha A Shah 30


recommended. Excessive dust generation should be avoided to minimize the risks of
explosion. Hypromellose is combustible.
15. Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe. Included in the FDA
Inactive Ingredients Guide (ophthalmic preparations; oral capsules, suspensions, syrups,
and tablets; topical and vaginal preparations). Included in nonparenteral medicines
licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal
Ingredients

Megha A Shah 31


5. LITERATURE REVIEW ON FLOATING MICROSPHERES :
17
Najmuddin M et al prepared floating microspheres of Ketoprofen by using Emulsion
solvent diffusion method using acrylic polymer like Eudragit L100 and Eudragit S100
with different drug:polymerratio.The formulation that contain drug :polymer (1:2) gives
excellent Micromericproperties,yield of microspheres, incorporation
efficiency,Invitrobuyoncy, and highest in vitro drug release in sustaind manner with
constant fashion over extended period of time for 12 hours.
18
KapoorDevesh et al developed floating microspheres of Captopril by using Solvent
evaporation method using different ratio of HPMC K4M and stirring speed of stirrer are
taken as independent variables in factorial design. It was observed that increase in
polymer concentration gives better formulation.from study concluded that HPMC K4M
can give better drug entrapment efficiency with improved In vitro drug release.

GhandhiNishant S. et al 19 developed Microballons of Piogitazone using Eudragit S100.
The concentration of Eudragit S-100 had significant impact on drug entrapment
efficiency and particle size. Evaluation of formulations, chosen as optimal from grid
searches, indicated that the formulation that contain (Polymer: drug ratio 2.84:1 and
stirring speed: 393 rpm) fulfilled maximum requisites because of better drug entrapment
efficiency, sustained release of the drug and optimum particle size.

Sarrof Rama et al20 developed oral in situgel ofMetformin Hydrochloride using various
concentration of Sodium alginate and Calcium carbonate as gas generating agent. Sodium
alginate which forms a gel when it comes in contact with simulated gastric fluid. The
formulation (1.25% sodium alginate, 3.75% Metformin, 1.5% calcium carbonate, 2.5%
sodium citrate) showed optimum drug release and the release was 90 % in 8 hours.
21
J Josephine LJ et al prepared Stavudine loaded floating microspheres using polymer
Eudragit RS100 as rate controlling membrane. The floating microspheres prepared were
found to be spherical and free flowing. The formulated floating microspheres remained
buoyant for more than 12h.
22
Dubey Manish et al prepare floating microspheres of Metformin Hydrochloride using
hydroxy propyl methyl cellulose (HPMC) and Eudragit RS100 polymers by emulsion

Megha A Shah 32


solvent evaporation technique. The kinetic study of prepared microspheresshowed
controlled drug release by matrix diffusion Process with zero order release rate kinetics
with good stability.
23
Jessyshaji et al prepared floating pulsatile microsphers of Aceclofenacintende for
chronopharmacotherapy. The microspheres were prepared by using Eudragit S100 and
Eudragit L100 using emulsion solvent evaporation method. Prepared microspheres give
better buyoncy in stomach with improved lag time and after that it gives immediate drug
release by bursting effect.
24
KamathShwetha S. et al prepared Floating microspheres of Rabeprazole sodium by
using HPMC K15M and Ethyl cellulose as a polymer. The prepared microspheres gives
better buyoncy, particle size of microspheres with high drug entrapment efficiency. From
study concluded that by using HPMC K15M gives better micrometric properties,
entrapment efficiency and In vitro drug release as compared to Ethyl cellulose.

DurgavaleAbhijeet A. et al 25 developed floating microspheres using Gas forming agent
and also HPMC K4M and Ethyl cellulose. The prepared microsphere exhibited
prolonged drug release (~ 12 hr) and remained buoyant for > 12 hr. Due to gas forming
agent like NaHCO3 and CaCO3 there is increase in drug entrapment efficiency during
process. In general, CaCO3 formed smaller and stronger floating beads than
NaHCO3.From study, It was demonstrated that although CaCO3 is a less effective gas-
forming agent than NaHCO3.
26
Paul Swati et al prepared sodium alginate floating pellets of Metronidazole using
HPMC K4M and HPMC K100LV as polymer. By using Extrusion spherinization
prepared pellets gives better floating properties and improved bioavailability if srug.
From study concluded that increasing polymer concentration to an optimum level, the
release rate (23.18%) of metronidazole was satisfactory but further increase causes
decrease of metronidazole release.

Patel Gaurang et al 3studied Floaltingmicrosphers as a novel tool for H2 recepterbloker.
He applied different mieroencapsulation approaches and also concluded that multiple
unit dosage form give uniform drug release as well as high surface area to volume

Megha A Shah 33


ratio.compared to single unit dosage fom. Also Microspheres are applicable for both oral
as well as parentral route.
35
Virendra Kumar Dhakar et al developed floating, pulsatile, multiparticulate of
aceclofenac using polymer of low methoxylated pectin, sodium alginate and gellan gum
and combination of them. Cross-linked beads were prepared by using above polymers by
acid base reaction during ionotropic gelation..Drug loaded multiparticulates were
subjected to various characterization and evaluation parameters like entrapment
efficiency, buoyancy study, surface topography. From the above evaluation studies, low
methoxylated beads contain high entrapment efficiency with about 90% drug release.

Mowafaq M. Ghareebet al36 prepared floating beads of Cinnarizine by the emulsion–
gelation method usingdifferent concentrations of sodium alginate and calcium chloride
and their influence on beads uniformity, buoyancy, and in vitro drug release was studied.
The results indicated formula B7 contain 3% w/v sodium alginate, 15% v/v oil and 0.1
M calcium chloride, showed a higher similarity factor (f2 =70.1) of CNZ release in
comparison to release from standard gastroretentive sustained release floating cinnarizine
tablet with good floating over duration of more than 12 hours.
37
Shashikant D. Barhate et al Formulated and evaluated of controlled release
metronidazole floating alginate beads using natural polymersby ionotropic gelation
method for the treatment of H. pylori. The optimized coating composition was achieved
with 0.9% chitosan, 1.5% k-carragennan and 1.52% HPMC E5. In vitro dissolution study
of factorial batches showed zero-order drug release.
38
Tarique Khan et al formulated & evaluated floating tablet of diltiazem HCl using
different concentrations ofpolymer (sodium carboxy methyl cellulose or hydroxyl propyl
methyl cellulose K4M, K15M) & different concentration of effervescent agents. The
formulation D4 shows 99% drug release at the end of 12 h in vitro and floating lag time
was 30 sec and tablet remained buoyant throughout studies.
39
Shiva Kumar Yellanki et al prepared Floating Alginate Beads of Riboflavinusing
different weight ratios of gas‐forming agent and sodium alginate.The formulation C3
exhibited the optimum sustained release of Riboflavin over a period of at least 10 h., with
excellent floating properties.From above studies it is concluded that floating alginate

Megha A Shah 34


microbeads can be a suitable approach to improve oral bioavailability of drugshaving
narrow absorption window in stomach.
40
Masareddy RS et al Developed Metformin Hcl Loaded Sodium Alginate Floating
Microcapsules Prepared by Ionotropic Gelation Technique with sodium bicarbonate as
gas forming agent,swellable polymers Hydroxy propyl Methylcellulose (HPMC E50),
Ethyl cellulose(EC) and calcium chloride gelling agent.All formulations possessed good
floating properties with total floating time more than 12 hrs ,spherical, good free flowing
high entrapment efficiency.

Megha A Shah 35


6. LITERATURE REVIEW ON ALFUZOSIN HCl :

LeelaManasa K et al 47 prepared Oro Dispersible tablet of Alfuzosin Hydrochloride by
direct compression and sublimation methods with a view to enhance patient compliance.
In these methods, varying concentrations of crospovidone, sodium starch glycolate and
croscarmellose sodium of 3.3, 6.6 and 10% w/w were used, along with camphor used as
subliming agent sublimation method In formulation containing 10% w/w Crospovidone
emerged as the overall best formulation (t50%1.79 and 1.21 minutes) based on drug
release characteristic in pH 6.8 phosphate buffer.
48
Chandana B et al prepared alfuzosin extended release (ER) tablets using
hydroxypropylmethyl cellulose (HPMC) and ethyl cellulose. Seven different
formulations were developed by wet granulation method using HPMC K100M and EC
7cps as polymers. All the formulations were evaluated for their micromeritic properties
such as compressibility index, Hauser’s ratio and flow properties. Dissolution studies of
showed that formulation F7 released 96% of drug at 20 h time interval. From the results,
it was shown that release followed first order kinetics.
49
Patil Sanjay B et al prepared sustained release floating pellets of alfuzosin
hydrochloride which has narrow absorption window in proximal intestine to improve
patient compliance and therapeutic efficacy in the treatment of benign prostatic
hyperplasia.The system was designed to provide drug loaded pellets coated with three
successive coatings over Celphere® (microcrystalline cellulose pellets) – drug layer,
effervescent layer (HPMC and sodium bicarbonate) and gas entrapped polymeric
membrane (Kollicoat® SR 30D).optimal formulation comprising of Kollicoat® SR 30D
(10%) and HPMC:sodium bicarbonate (1:4) was identified to provide desired values for
FLT of 4.16 min and percentage drug released at a 10 h (92.85%).

Megha A Shah 36


7. EXPERIMENT WORK
Materials Used In Present Investigations

Table 7.1 Materials used in present investigations

Excipients Source

Alfuzosin HCl (drug) Sun pharmaceutical pvt.ltd.
Eudragit S 100 Lesar chemicals,Ahmedabad.
Ethocel 20cps, 45cps Colorcon Asia Pvt. Ltd., Goa
HPMC K 100M Colorcon Asia Pvt. Ltd., Goa
Span 80 Chemdyes corporation
Tween 80 Finar chemicals ltd,Mumbai.
Dichloromethane Finar chemicals ltd,Mumbai.
Methanol Finar chemicals ltd,Mumbai.
Ethanol Finar chemicals ltd,Mumbai.
Liquid Paraffin Finar chemicals ltd,Mumbai.

Instruments Used In Present Investigations

Table 7.2 instruments used in present investigations

Instrument Supplier

UV-VIS double beam Shimadzu UV-1601, Kyoto,
Spectrophotometer Japan.
Analytical balance Shimadzu, Japan.
Overhead stirrer Remi Motors Ltd. Mumbai.
Dissolution test TDT-06T apparatus Electrolab, Mumbai, India.
FTIR Shimadzu, Japan.

7.1 PREFORMULATION STUDY
Preformulation can be defined as investigation of physical and chemical properties of
drug substance alone and when combined with excipients.

Megha A Shah 37


Preformulation studies are the first step in the rational development of dosage form of a
drug substance. The objectives of Preformulation studies are to develop a portfolio of
information about the drug substance, so that this information is useful to develop
formulation.

Preformulation studies are designed to identify those physicochemical properties and
excipients that may influence the formulation design, method of manufacture,
pharmacokinetic and biopharmaceutical properties of the resulting product.

The following test were performed for preformulation study:-

A.Physical State
C.Solubility
D.Melting Point

7.1.1Characterization of Alfuzosin HCl
 Description: white to off-white crystalline powder

 Identification: IR spectroscopy -Determined by infrared absorption
spectrophotometry.Compare the spectrum with that obtained with the reference
spectrum of Alfuzosin HCl.

80
%T
70

60

50

40

30

20

10

3900 3600 3300 3000 2700 2400 1950 1800 1650 1500 1350 1200 1050 900 750 600 450
Alfuzocin 1/cm

 UV absorption spectroscopy – Standard Stock solution of Alfuzosin HCl was
scanned for absorption between 200-400 nm by means of double beam UV visible
spectrophotometer.
Alfuzosin HCl exhibited UV Absorption maxima at 244nm(λmax)0.1 N HCL.

Megha A Shah 38


 Solubility:freely soluble in water, sparingly soluble in alcohol, and practically
insoluble in dichloromethane.
 Melting point:The melting point of Alfuzosin HCl was found out by capillary method
using Thiele’s tube melting point apparatus and was compared with the literature
survey.
Melting range: 235 to 240°C.

Figure 7.1: UV spectra of Alfuzosin HCl in 0.1N HCl.

7.1.2 Drug Excipient Compatibility Study
Drug- excipients interactions play a vital role in the release of drug from formulation.
Fourier transform infrared spectroscopy has been used to study the physical and chemical
interactions between drug and the excipients used. Fourier transform infrared (FTIR)
spectra of Alfuzosin HCl, Eudragit S100, HPMC K100 M were recorded using KBr
mixing method on FTIR instrument of the institute (FTIR-8400S, Shimadzu, Kyoto,
Japan).
7.2 METHOD OF ANALYSIS OF DRUG
7.2.1 PREPARATION OF REAGENTS
Preparation of 0.1 N HCl

Megha A Shah 39


Measure accurately 8.5 ml of concentrated hydrochloric acid using 10 ml pipette. Dilute
it up to 1000 ml with distilled water in 1000 ml volumetric flask.
Preparation of standard calibration curve for Alfuzosin HCl in 0.1 N HCl
Accurately weighed 100 mg Alfuzosin HCl was transferred to 100 ml volumetric flask
and was dissolved in 20 ml 0.1N Hydrochloric acid. The volume was made up to the
mark with 0.1N hydrochloric acid to prepare a stock solution of 1000 µg/ml (SS-1). From
this SS-2 was prepared containing 100µg/ml. The above stock solution (SS-2) was further
diluted with 0.1 N Hydrochloric acid to get the concentration of Alfuzosin HCl1,2,3,4,5,6
and 7 µg/ml.. The absorbance of the solutions was measured against 0.1 N HCl as a blank
at 244 nm using double beam UV visible spectrophotometer. The graph of absorbance v/s
concentration ( g/ml) was plotted and data was subjected to linear regression analysis in
Microsoft Excel®. The results of standard curve preparation are shown in Table 7.1, and
Figure 7.3.

Concentration Absorbance
( g/ml)
0 0
1 0.148
2 0.274
3 0.383
4 0.490
5 0.626
6 0.718
7 0.820

Correlation coefficient = 0.996
Absorbance = = 0.116 × concentration + 0.026

Table 7.1: Standard curve of Alfuzosin HCl in 0.1 N HCl at 244nm.

Megha A Shah 40


0.9
0.8
0.7
0.6
Absorbance 0.5
0.4 y = 0.116x + 0.026
0.3 R² = 0.996
0.2
0.1
0
0 1 2 3 4 5 6 7 8
Concentration (µg/ml)

Figure 7.2: Standard curve of Alfuzosin HCl in 0.1 N HCl at 244 nm.

7.3 PRELIMINARY SCREENING
7.3.1 Selection of polymer
Review of literature reveal that Ethyl cellulose ( 20 cps, 45 cps), Polymethacrylates
(Eudragits) like Eudragit S 100, Eudragit RS 100 and Methocel are used for the
formulation of Floating microspheres for sustained release of drug.

7.3.2 Preparation of preliminary batches of Alfuzosin HCL Floaing Microspheres:
Microspheres were prepared by Emulsion solvent evaporation method. Alfuzosin HCl
and Different polymers with drug to polymer ratio ( 1:2,1:3, 1:4, 1:5, 1:6, 1:9) are
dissolved in organic solvent like Dichloromethane : Eyhanol (1:1) or Dichloromethane :
methanol (1:2) to get dispersed phase. When solvent with dielectric constant 10 or above,
non polar Liquid paraffin is prepared as disperingmedium.mixture of drug and polymer
was poured in 200 ml Liquid paraffin containing Span 80 as droplet stabilizer and stirred
at 900 rpm for 3 hr. During this time solvent was completely removed by evaporation.
The solidified microspheres were filtered, washed five times with 20ml petroleum ether,
dried under vaccum at a room temperature for 12 hr.

Megha A Shah 41


FORMULATION FORMULATION BATCH CODE
INGREDIENTS(mg) F1 F2 F3 F4 F5 F6 F7

Alfuzosin HCl 100 100 100 100 100 100 100
Ethocel 20 Cps 400 - - - - - -
Ethocel 45 Cps - 400 - - - - -

Eudragit RS - - 500 - - - -
Eudragit S 100 - - - 450 550 810

Methocel K 100M - - - 50 50 90
Dichloromethane (ml ) 10 10 10 5 5 5 5

Ethanol 10 10 10 - - - -
Methanol - - - 10 10 10 10
Span 80 - - 0.25% 0.25% 0.25% 0.25% 0.25%

Tween 80 0.25% 0.25%

Table 7.2: Formulation of preliminary batches

7.4 Evaluation parameter of Microspheres:
Particle Size Analysis:-
The size of microparticles of each batch was measured by using a calibrated micrometer
attached with a microscope and the average diameter was calculated.

Quantitative analysis of Alfuzosin HCl contents in hollow microspheres:-
50mg of hollow microspheres were taken and 50 ml of methanol was added on it and
after this 1 ml of solution was taken in a 10 ml of volumetric flask and volume was made
up to 10 ml using methanol. An absorbance of the solution was assayed by UV
spectrophotometer at wavelength 244 nm, using methanol as a blank. An amount of
Alfuzosin HCl was calculated from the calibration curve. The analysis was performed in
triplicate. The percent of production yield of the hollow microsphere, percent of drug
content, percent of theoretical content, and percentage of drug entrapment were

Megha A Shah 42


calculated from the following equation:-
% Yield = Total weight of microspheres x 100
Total weight of drug and Polymers

% Drug Loading = Quantity of drug present in microspheres x 100
Weight of micosphers

% drug entrapment efficiency = Quantity of drug encapsulated in microspheres x 100
Total quantity of drug utilized for encapsulation

Floating Ability :-

First 50 mg of the hollow microspheres were placed in 50 ml beaker. Second, 20 ml of
0.1 M HCL containing 0.02% Tween 20 were added and stirred with a magnetic stirrer at
37 ± 0.5 0C. Floating microspheres were collected after 24 hr. The experiments were
performed in triplicate and the percentage floating of the hollow microspheres was
calculated from the following equation:-

% floating of hollow microspheres = Weight of floating microspheres x 100
initial weight of hollow microspheres

In Vitro Dissolution Study
The release profile of the microspheres were studied in 0.1 N HCl (pH 1.2) using the USP
Type II Apparatus (Basket type) Method. An accurately weighed amount of microspheres
equivalent to 10 mg of Alfuzosin HCl was added to 900 ml of dissolution medium at
37±0.5ºC and stirred at 50 rpm.Samples of 5 ml were removed and replaced with fresh
medium at appropriate time intervals and assayed spectrophotometrically at 244 nm.

Megha A Shah 43


7.5 RESULTS AND DISCUSSION
7.5.1PREFORMULATION STUDY
7.5.1.1 Drug Excipient Compatibility Study
Drug- excipients interactions play a vital role in the release of drug from formulation.
Fourier transform infrared spectroscopy has been used to study the physical and chemical
interactions between drug and the excipients used.

Megha A Shah 44


7.6.2 PRELIMINARY SCREENING
7.6.2.1 Selection of polymer
In present investigation attempt was made to prepare formulation of Alfuzosin HCl
Microspheres using Ethyl cellulose ( 20 cps, 45 cps), Polymethacrylates (Eudragits) like
Eudragit S 100 and Methocel K 100M usin Emulsion solvent evaporation method.
In preliminary study, different batches were prepared as per the composition given in
Table 7.2. All the batches were evaluated for in vitro dissolution study as per the
procedure given in section 7.4. Different other evaluation parameters were also studied.

FORMULATION BATCH CODE
Parameters
F1 F2 F3 F4 F5 F6

Drug Loading (%) 19.22 14.22 14.6 13.66 8.6

Drug Entrapment
91.88 66.84 78.11 90.70 68.45
Efficiency (%)

% Yield 95.6 94 89.66 94.85 79.6

Floating time 7 hr 8 hr 8 hr 10 hr 12 hr

Table 7.3: Evaluation parameters of F1 to F6 for preliminary screening

Table 7.10: Cumulative percentage drug release (CPR) from tablets for preliminary
screening

TIME CPR
(hr)
F1 F2 F3 F4 F5 F6
0.00 0.00 0.00 0.00 0.00 0.00
0
87.88 89.44 66.93 57.28 56.11 31.57
1
98.91 93.03 83.95 68.25 62.79 35.76
2
108.59 107.61 90.41 76.62 69.01 40.78
3
92.24 92.03 75.76 42.84
4
94.41 93.86 78.14 49.54
5
102.59 98.04 91.3 60
6

Megha A Shah 45


97.68 72.95
7
84.94
8
92.87
9
96.01
10
102.15
11

12

13

14

15

16

Megha A Shah 46


7. FUTURE PLAN OF RESEARCH WORK
Phase-I: Analytical Method Development

Phase-II: Preformulation Study

Physical characteristics of drug
 Organoleptic evaluation
Solubility
 Determination of solubility

Phase-III: Formulation and Development.
Screening of the polymers for total and proportional amount for
desired drug release.
Study the effect of different fillers on the release of the drug.
Optimization of drug to polymer ratio and polymer to polymer
ratio.

In process Quality control tests & properties of Formulation.

I. Particle size determination
II. Drug entrapment efficiency
III. Percent yield

Phase-IV: Compatibility Study
Drug-excipient compatibility will be check by comparing FTIR spectra or DSC
thermo gram of pure drug and FTIR spectra or DSC thermo gram of the physical
mixture of drug and excipient.

Phase-V: In-Vitro Drug release study

Phase-VI: stability study

Megha A Shah 47


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