EVALUATION OF SUSTAINED RELEASE PRODUCTS

Sustained Action Dosage For Are Tested:
Stability of the availability rate during storage
In vivo sustaining action
In vitro sustaining action
In Vivo Evaluation of Sustained Action:
In clinical trials versus time in a living system
Design and Method of Evaluation are in the scope of pharmacology .
In Vitro Evaluation of Sustaining Action:
Being quick
Is required as a routine control for sustained action
For these reason: considerable effort had gone into the design and evaluation of apparatus and methods.
STOLL HERSCHBERG TABLET DIS.APPARATUS:
Simplest system
Using 200ml of menstrum
Modified with a 40 mesh sieve to retain the finer particles of the dosage form
Dosage forms are placed in tubes
The gentle agitation started
The residue in the tubes is analyzed at 1to 2 hour intervals beginning at ½ hour ending at 8 to 10 hours after starting
SOUDER & ELLENBOGEN METHOD:
A sample of sustained action dosage form is placed in 90ml cylindrical screw capped bottle with 60ml of menstrum
Rotated slowly slowly
In a 37 C controlled temp.in water bath
The residual drug is analysed at several intervals
Initail analysis is usually made after ½ hour and final analysis after 8-10 hours of rotation
In Vitro system used for evaluation of availability from sustained release dosage forms usually involve 5 factors:
A limited quantity of menstrum
Adjusted to app. PH
Tonicity
Enzymatic content of absorption fluid
Agitated at body temp.