OCULAR DRUG DELIVERY

1. SCHOOL OF PHARMACEUTICAL SCIENCES
RAJIV GANDHI PROUDYOGIKI
VISHWAVIDYALAYA
OCULAR DRUG DELIVERY
SYSTEM
SUBMITTED BY:-
SAURABH SHARMA
0001PY18MP14
GUIDED BY:-
Mr. RAHUL MAURYA

2. CONTENTS
2
 INTRODUCTION
 ANATOMY OF EYE
 ROUTES OF DRUG DELIVERY THROUGH EYE
 OCCULAR ABSORPTION PATHWAY
 MECHANISM OF OCCULAR ABSORPTION
 FACTORS AFFECTING INTRAOCCULAR
BIOAVAILABILITY
 FORMULATION CONSIDERATION
 EVALUATION OF OCCULAR DRUG DELIVERY SYSTEM

3. INTRODUCTION
3
 Ocular administration of drug is primarily associated with the
need to treat ophthalmic diseases.
 Eye is the most easily accessible site for topical
administration of a medication.
 Ideal ophthalmic drug delivery must be able to sustain the
drug release and to remain in the vicinity of front of the eye
for prolong period of time.

4. ANATOMY OF EYE
4

5. ROUTES OF DRUG DELIVERY IN EYE
5

6. PATHWAY
6
DRUG IN TEAR FLUID
OCULAR ABSORBTION SYSTEMIC ABSORPTION
(50% - 100% OF DOSE)
MAJOR ROUTES
-CONJUCTIVA OF EYE
-NOSE
MINOR ROUTES
-LACRYMAL DRAINAGE
- PHARYNX
- GI TRACT
-SKIN OF NECK
CORNEAL
ROUTE
CONJUCTIVAL AND
SCLERAL ROUTE
- LARGE
HYDROPHILIC
DRUGS
AQUEOUS
HUMOR
OCCULAR TISSUE

7. MECHANISM OF OCULAR
ABSORPTION
7
Non- corneal absorption:
 Penetration across sclera
& conjunctiva into
intraocular tissues.
 Non productive: because
penetrated drug is
absorbed by general
circulation.
Corneal absorption:
 Outer epithelium: rate
limiting barrier, with pore
size 60a, only access to
small ionic and lipophilic
molecules.
 Trans cellular transport:
transport between corneal
epithelium and stroma.

8. FACTORS AFFECTING
INTRAOCULAR BIOAVAILABILITY
8
 Inflow & outflow of lacrimal fluids.
 Efficient naso-lacrimal drainage.
 Interaction of drug with proteins of lacrimal fluid.
 Dilution with tears.
 Corneal barriers.
 Active ion transport at cornea.

9. FORMULATION
CONSIDERATION
9
Physicochemical properties of drug:
It includes the factors that affect the corneal permeability of
the drug. Eg. Lipophilicity of the drug and molecular size
and shape.
Buffer Capacity and pH:
Normal tear fluid pH is 7.4 so pH should be chosen to
optimized drug stability.
When pH deviates from 7.4 it is important to be aware of
buffer capacity to minimize lacrimation and irritation

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 Tonicity adjustment:
Tonicity needs to be adjusted so that it exerts an osmotic pressure
equals to that of tear fluid ( equivalent to 0.9% of NaCl ideally).
Opthalmic solution are hypotonic to enhance absorpton and provide
concentration of active ingredient sufficient to achieve efficacy.
Common tonicity adjusting agents are NaCl, Cl, d – mannitol ,
propylene.
• Antioxidants:
They are common;y added to migrate oxidation issues.
Exampole: Sodium bisulfite or metabisulfite is used in concentration up
to 0.3% in epinephrine hydrocloride.

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 Surfactant:
Several nonionic surfactant are used in relative low
concentration to achieve drug solubility Eg. Polysorbate,
Tyloxapol, Polyxyl 40 stearate.
The order of surfactant toxicity is Anioinic >cationic >nonionic.
 Preservatives :
It help to prevent contamination of the bottle contents over the
cource of multiple uses.
Bezalkonium chloride is the commonly used opthalmic
preservatives and is used in 72% of opthalmic solutions.

12. EVALUATION OF ODDS:
12
Physical characterization
The physical characteristics of ocular films such as color,
texture, flexibility and appearance were evaluated.
Uniformity of weight
From each batch, 3 films should be weighed individually using
digital balance . The mean weight of the films was recorded.
Uniformity of thickness
The thickness of films was determined using a Vernier caliper .
For each formulation, the thickness of 3 randomly selected films
should tested .

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Drug content detemination
Ocular films (3 samples) should be taken from each batch and
dissolved using 50 mL of isotonic phosphate buffer pH 7.4 (tear
fluid) into volumetric flask. The absorbance of solution after
filteration and required dilution was measured by UV-VIS
spectrophotometer at 283 nm. The mean drug content of films was
determined considering the concentartion of the solution and the
number of films dissolved.
In-vitro drug release study
The in-vitro drug release from different ocular films is studied using
the vial method. Each film was placed in a vial containing 10 mL of
simulated tear fluid (pH 7.4) which was previously warmed at 37 ±
1°C. These vials were positioned over a Kottermann 4020 shaker.
To simulate the eye blinking, the shaker was kept at its minimum
shaking speed. Aliquot of samples at specific time intervals was
withdrawn and the equivalent amount of fresh fluid was replaced.
The samples were analyzed at 283 nm using UV
Spectrophotometer after appropriate dilutions against reference
using isotonic phosphate buffer pH 7.4 as blank.

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Mucoadhesion study
The mucoadhesion time is studied by application of ocular
films on a freshly cut sheep eyelid. Ocular film was attached to
the mucosal surface of the eyelid fixed on the bottom of a
beaker by applying a light force with a fingertip for 20 s. The
beaker was filled with 100 mL of bicarbonate Ringer solution
pH 7.4 and stirred at a rate of 150 rpm at room temperature .
Mucoadhesion time was the time needed for complete
detachment of the film from the mucosal surface.

15. ADVANTAGES OF ODDS
15
 They are easily administered by the nurse
 They are easily administered by the patient himself.
 They have the quick absorption and effect.
 Less visual and systemic side effects.
 Increased shelf life.
 Better patient compliance.

16. DISAVANTAGES
16
 The very short time the solution stays at the eye
surface.
 Its poor bioavailability.
 The instability of the dissolved drug.
 The necessity of using preservative.

17. REFERENCES
17
 https://www.slideshare.net/HaiderZaman6/the-
physiology-of-human-eye
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4499423/
 https://www.slideshare.net/RikeshlalShrestha/ocular-
drug-delivery-system-ppt
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4289909/

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