1. Evaluation of tablet dosage form 5) dissolution
Aram I. Ibrahim
University of Sulaimani
College of Pharmacy
Dep. Of Pharmaceutics

2. Content Introduction Importance Apparatus Dissolution medium Agitation
Calibration curve
Procedure

3. Introduction
Drug absorption from a solid dosage form after oral administration depends on the release of the drug substance from the drug product, under physiological conditions.
Tablet Dissolution is a standardised method for measuring the rate of drug release from a dosage form.

4. Importance To show the release of drug from the tablet
To show that the rate of drug release is uniform batch to batch.
To show that release is equivalent to those batches proven (Brand).

5. Apparatus The most commonly employed dissolution test methods are :
The basket method (Apparatus 1)
The paddle method (Apparatus 2)
The basket and the paddle methods are simple, robust, well standardized, and used worldwide.

6. Apparatus Apparatusa Name Drug Product Apparatus 1 Rotating basket
Tablets
Apparatus 2
Paddle
Tablets, capsules, modified drug products, suspensions
Apparatus 3
Reciprocating cylinder
Extended-release drug products
Apparatus 4
Flow cell
Drug products containing low-water-soluble drugs
Apparatus 5
Paddle over disk
Transdermal drug products
Apparatus 6
Cylinder
Apparatus 7
Reciprocating disk
Rotating bottle
(Non-USP)
Extended-release drug products (beads)
Diffusion cell (Franz)
Ointments, creams, transdermal drug products

7. Dissolution Medium
Dissolution testing should be carried out under physiological conditions, if possible.
This allows interpretation of dissolution data with regard to in vivo performance of the product. However, strict adherence to the gastrointestinal environment doesn't need to be used in routine dissolution testing.

8. Dissolution Medium
The volume of the dissolution medium is generally 500, 900, or 1000 mL.
Sink conditions are desirable.
An aqueous medium with pH range 1.2 to 6.8 should be used.
To simulate intestinal fluid (SIF), a dissolution medium of pH 6.8 should be employed.

9. Agitation
In general, mild agitation conditions should be maintained during dissolution testing.
Using the basket method, the common agitation (or stirring speed) is rpm; with the paddle method, it is rpm.

10. Preparation of calibration curve
Preparation of calibration solutions:
Prepare 5 calibration solutions meeting the entire interval of the measured concentration.
For this purpose, calculate the maximal theoretical concentration of the API, which can arise during the dissolution test.
Increase this value by 100mg/l and split the resulting interval to the four equal parts.
c1 = cmax mg/l
c2 = c1*3/4 mg/l
c3 = c1*1/2 mg/l
c4 = c1*1/4 mg/l
C5 = c1*1/8 mg/l

11. Preparation of calibration curve
Determine the amount of paracetamol in the sample using UV spectrophotometer

12. Procedure
Put the tablet in the dissolution jar, which contains 900ml dissolution media (DW).
Turn the device on, set the temp at 37, and run for one hour.
Take sample at predetermined time, after 5, 10, 20, 30 minutes, replace with fresh media.
Read absorbance of your samples, and calculate the amount of drugs in each sample.