ABSTRACT
Defined test procedures and specifications for testing topically applied drug products are required to ensure that products are manufactured to an appropriate quality so that they are safe and efficacious when they are released to the market and remain so through their shelf life. The relationship between crystal formation or crystal growth and drug product performance is dependent upon the drug product. Transdermal delivery systems are formulated with an adhesive in order to maintain intimate contact with the skin and allow delivery of the desired dose of drug. The transdermal delivery system is applied to the substrate in a controlled manner and is conditioned for specified time and temperature. Food and Drug Administration has included a clinical demonstration of non-inferior adhesion as part of the bioequivalence recommendation for specific transdermal products. As with semisolid dosage forms, a performance test for transdermal delivery systems must have ability to measure drug release from the finished dosage form, must be reproducible and reliable.
