USP DISSOLUTION APPARATUS TYPES
Dissolution is an important quality control test that is done before releasing the product into the market. there are different types of dissolution apparatus used for testing tablets, capsules, patches, etc. The selection of a specific apparatus depends on the type of product, and the USP National Formulary describes the official dissolution apparatus.
Here are the USP NF official dissolution Apparatus
- Rotating basket type
- Paddle
- Reciprocating cylinder
- Flow cell
- Paddle over disk
- Cylinder
- Reciprocating disk
NON-USP -NF Dissolution Apparatus include – Rotating Bottle apparatus & Franz diffusion cell
Rotating basket (Apparatus-1) – here a small cylindrical basket will rotate, and the agitation method is the Rotating Stirrer. The test sample is placed in the basket, and it is rotated by a motor shaft in the round bottom flask with dissolution medium at an rpm of 100 -150, and a temperature of 37 degrees Celsius.
Apparatus -2 is a paddle type in which the paddle will rotate, and the tablet is kept in round bottom flask containing dissolution medium and positioning of paddle is very important, and this is the most common method we have seen during our education. In industry based on requirement the apparatus used varies, RPM Is 50 or 75 is general operating speed at constant temperature of 37 degree Celsius maintained in water bath.
Apparatus -3 named Reciprocating cylinder as the cylinder reciprocates up and down in the flat-bottomed glass vessels and it is used for modified release dosage forms.
Apparatus -4 it’s called flow through cell as dissolution medium flows through the chamber containing test sample, having a flow rate of 4-32ml/min and this achieved with help of pump, and it is used for modified release dosage forms.
Apparatus -5 Paddle over disk is used for transdermal products and it consist of steel disk on which the test sample is placed and upon it the paddle rotates, hence the name paddle over disk and the samples are drawn midway between the paddle and disk and test is run at 32-degree Celsius temperature in the medium.
Apparatus – 6 Cylinder apparatus is modified form of basket apparatus, where basket is replaced with cylinder and is used for testing transdermal products.
Apparatus -7 Reciprocating disk is also used for testing transdermal products, where the sample is mounted on the disk and is attached to shaft, and it reciprocates up and down in the reciprocating cylinder apparatus.