An overview of in vitro dissolution testing for film dosage forms

Films are a rapidly developing new dosage form, with dozens of products marketed worldwide in the past two decades. Dissolution is a critical quality attribute of film dosage forms. Dissolution tests are used extensively to evaluate film products quality and performance across drug development and manufacturing, including routine quality control for pharmaceutical development and batch release, stability studies, prediction of in vivo performance, and biowaiver requests. There are many important factors to consider when developing and implementing dissolution tests for film dosage forms, such as apparatus selection, media type and volumes, rotation speed, and sampling times. This review introduces the dissolution apparatuses suitable for film dosage forms, summarizes dissolution methods used for commercial drug products and reported in the literature, discusses the application and significance of dissolution testing in development and evaluation of film drug products, such as commercial films marketed in the US and Japan, and provides a perspective on the future of dissolution testing for films.