In Vitro Release Tests and Equivalence Evaluation for Topical Semisolid Dosage Forms

Topical semisolid dosage forms include cream, ointment and gel. The release of active pharmaceutical ingredient (API) is of critical importance for the quality of topical semisolid drug products. Their drug release depends largely on the formulation and manufacturing process. In vitro release test(IVRT) can be used to evaluate the release rate of API, and to detect the difference between the release rate that may be caused by the changes in the formulation and the differences in the physical and chemical properties of API. A large number of studies have shown that differences in IVRT method parameters will affect the IVRT results, so the consistency of the IVRT method parameters can ensure the reliability of the results. This article discusses development and verification of IVRT method, the experimental procedures and data statistical analysis methods for the equivalence evaluation of generic semisolid dosage forms.