Dissolution testing is important for quality control and predicting in vivo performance of drug products. It quantifies the rate and amount of drug released from solid oral dosage forms under standardized conditions. Key factors in designing a dissolution test include the apparatus, media, and acceptance criteria. The most common apparatuses are USP Type I (baskets), Type II (paddles), and Type IV (flow-through cells). Media include water, buffers, and simulated gastric/intestinal fluids. Acceptance criteria ensure a minimum percentage of drug dissolves within a specified time for quality batches. Dissolution testing is critical for developing and evaluating conventional and controlled-release drug products.

1. Dissolution Testing for Conventional
and Controlled Release Products
Presented by:
MD.FIAZ
M.Pharm.(PAQA)
Guided by:
Mr.R.Balaji Reddy,M.Pharm.
(Department of Pharmaceutics)

2. Overview:
• Introduction
• Importance and need for dissolution testing
• Theories of drug dissolution
• Dosage forms requiring dissolution
• Factors for designing dissolution test
• Dissolution media
• Official Dissolution Apparatus
• Dissolution testing methods
• Conclusion

3. Introduction
Dissolution is a process in which a solid substance solubilizes
in a given solvent i.e. mass transfer from the solid surface to
the liquid phase.
Rate of dissolution- It is the amount of drug substance that
goes in solution per unit time under standardized conditions
of, temperature, pH and solvent composition and constant
solid surface area.
The rate of dissolution quantifies the speed of the dissolution
process.

4. Importance & need for Dissolution Testing
Fig.-Disintegration, deaggregation, and dissolution stages as a drug leave a tablet or granular matrix.
Granules or
aggregates
Tablet or
Capsules
Fine
particles
Drug in
solution
(in vitro or
in vivo)
Drug in
blood, other
fluids , and
tissues
Disintegration
Deaggregation
Dissolution Absorption
(in vivo)

5. Dissolution testing is of utmost importance in following aspects-
 As reliable Predictor of in vivo dissolution performance of drug.
 A Rate limiting factor in determining the physiological availability of
drug.
 As Quality control tool for monitoring the uniformity and reproducibility
of production batches.
 As Research tool in optimizing parameters and ingredients in new drug
formulation.
 It is widely accepted as animal experimentation has been restricted under
the Act of Prevention of cruelty of animals.
Importance & need for Dissolution Testing

6. Theories Of Drug dissolution
Diffusion layer model/Film Theory.
Danckwert’s model/Penetration or surface
renewal Theory.
Interfacial barrier model/Double barrier or
Limited solvation theory.

7. Dosage forms requiring dissolution
• Tablets (coated and uncoated).
• Capsules
• Suppositories
• Suspensions
• Topical dosage forms like creams ,gels, ointments,
etc .
• Transdermal patches.

8. Factors for designing dissolution test:
1) Factors related to the dissolution apparatus:
 size of container (several ml to liters )
 shape of container (round bottomed or flat)
 nature of agitation (stirring, rotating or oscillation )
 speed of agitation performance precision of the apparatus etc.
2) Factors related to the dissolution fluid (media):
 Composition of dissolution media (pH range 1- 8, water etc)
 Temperature
 Viscosity
 Volume
 Sink condition
 Non-sink condition

9. 3) Process parameters:
 Method of introduction of dosage form
 Sampling techniques
 Changing dissolution media
Factors for designing dissolution test:

10. Dissolution media
Common dissolution media used (suggested by different guidelines):
 Purified water.
 Diluted acid (o.1 N HCl ).
 Buffered aqueous solutions.
 Simulated gastric fluid (with or without enzymes).
 Simulated intestinal fluid (with or without enzymes)
Factors effecting selection of dissolution media:
 Dissolved gases
 Composition of dissolution media
 ph of dissolution media
 Viscosity of dissolution media
 Surfactant
 Temperature

11. Official Dissolution Apparatus
USP Type- I Basket Type
USP Type- II Paddle Type
USP Type- III Reciprocating Cylinder
USP Type- IV Flow Through Cell
USP Type- V Paddle Over Disk
USP Type- VI Rotating Cylinder
USP Type- VII Reciprocating Holder

12. Official Dissolution Apparatus
USP TYPE I: BASKET TYPE APPARATUS

13. Official Dissolution Apparatus
USP TYPE II : PADDLE TYPE APPARATUS

14. Official Dissolution Apparatus
USP TYPE III : RECIPROCATING CYLINDER

15. Official Dissolution Apparatus
USP TYPE- IV : FLOW THROUGH CELL
USP TYPE V : PADDLE
OVER DISK APPARATUS

16. Official Dissolution Apparatus
USP TYPE VI : ROTATING CYLINDER
USP TYPE VII:
RECIPROCATING HOLDER

17. Dissolution testing methods
CONVENTIONAL & PROLONGED-RELEASE DOSAGE
FORMS
Place the dissolution medium into the vessel(free from dissolved air)
Assemble the apparatus and warm the dissolution medium to 36.5º to 37.5º.
Place one dosage unit in the apparatus
Allow the tablet or capsule to sink to the bottom of the vessel prior to the rotation
(PADDLE TYPE APPARATUS)
OR
Place the tablet or capsule in a dry basket at the beginning of each test and lower the
basket into position before rotation(BASKET TYPE APPARATUS)
Operate the apparatus immediately at the speed of rotation specified

18. At each of the times stated, withdraw a specimen from a zone midway
between the surface of the dissolution medium and the top of the rotating
blade or basket, not less than 10 mm from the wall of the vessel.
For each of the tablet or capsule tested, calculate the amount of dissolved
active ingredient in solution as a percentage of the stated amount .
Dissolution testing methods

19. ACCEPTANCE CRITERIAS
CONVENTIONAL RELEASE DOGASE FORMS:
*D is the amount of dissolved active ingredient specified in the individual monograph, expressed as a percentage of the labeled content.
**Percentages of the labeled content.
Dissolution testing methods
Level Number tested Acceptance criteria
S1
S2
S3
6
6
12
Each unit is not less than D* + 5 percent**.
Average of 12 units (S1 +S2) is equal to or
greater than D, and no unit is less than D –
15 per cent**.
Average of 24 units (S1+S2+S3)is equal to
or greater than D, not, More than 2units are
less than D – 15 per cent** and no unit is
less than D – 25 per cent**.

20. PROLONGED-RELEASE DOSAGE FORMS
Dissolution testing methods
Level Number tested Acceptance criteria
L1
L2
L3
6
6
12
No individual value lies outside each of the stated
ranges and no individual value is less than the
stated amount at the final test time.
The average value of the 12 units (L1 +L2) lies
within each of the stated ranges and is not less than
the stated amount at the final test time; none is
more than 10per cent of labeled content outside
each of the stated ranges; and none is more than 10
per cent of labeled amount below the stated amount
at the final test time.
The average value of the 24 units (L1 +L2 + L3)
lies within each of the stated ranges, and is not less
than the stated amount at the final test time; not
more than 2 of the 24 units are more than 10per
cent of labeled content outside each of the stated
ranges; not more than 2 of the 24 units are more
than 10 per cent of labeled content below the stated
amount at the final test time; and none of the units
is more than 20 per cent of labeled content outside
each of the stated ranges or more than 20 per cent
of labeled content below the stated amount at the
final test time

21. TRANSDERMAL PATCHES
Place the prescribed volume of the dissolution medium in the vessel and
equilibrate the medium to the prescribed temperature.
Apply the patch to the SSDA by adhesive
Place the patch mounted on the SSDA flat at the bottom of the vessel with the
release surface facing upwards.
Immediately rotate the paddle at 100 r/min
At predetermined intervals; withdraw a sample from the zone midway
between the surface of the dissolution medium and the top of the blade, not
less than 1 cm from the vessel wall.
Dissolution testing methods

22. Perform the assay on each sample, correcting for any volume losses, as
necessary. Repeat the test with additional patches.
Dissolution testing methods

23. According to USP apparatus used are
Dissolution testing methods
USP
APP.
DESCRIPTION ROT.
SPEED
DOSAGE FORM
I BASKET 50-120 rpm IR, DR, ER
II PADDLE 25-50 rpm IR, DR, ER
III RECIPROCATING
CYLINDER
6-35 rpm IR, ER
IV FLOW-THROUGH
CELL
N/A ER, POORLY
SOLUBLE API
V PADDLE OVER
DISK
25-50 rpm TRANSDERMAL
VI CYLINDER N/A TRANSDERMAL
VII RECIPROCATING
HOLDER
30 rpm ER

24. Conclusion
• Dissolution testing has become an integral part of quality
control.
• Although official methods are used, there exists no standard
method for evaluation of a solid dosage form.
• The method and standards, which correlate well with the in-
vivo data, should be utilized.
• The knowledge not only acts as tool for quality control, it also
assists in preformulation studies and in understanding the
biopharmaceutical role of the same.

26. References:
 United State Pharmacopoeia, The National Formulary, 2002, 20th Edition, United
State Pharmacopoeial Convention INC, Washington, 711, 2011.
 INDIAN PHARMACOPOEIA 2007 Volume 1, The Indian Pharmacopoeia
Commission, Ghaziabad, 179-181.
 Remington, The Science And Practice of Pharmacy, Volume 1, 21st Edition, Indian
Edition, B. I. Publications Pvt. Ltd., 654-665.
 Banakar, U.V. 2000, Pharmaceutical Dissolution Technologies , volume 49. Marcel
Dekker INC, N.Y., 174-175,280.
 Subramanyam C.V.S. 2006, Textbook Of Physical Pharmaceutics, 2nd Edition ,
Vallabh Prakashan,Delhi,88-90 .