An update on pharmaceutical film coating for drug delivery.

INTRODUCTION: Pharmaceutical coating processes have generally been transformed from what was essentially an art form in the mid-twentieth century to a much more technology-driven process. AREAS COVERED: This review article provides a basic overview of current film coating processes, including a discussion on polymer selection, coating formulation additives and processing equipment. Substrate considerations for pharmaceutical coating processes are also presented. EXPERT OPINION: While polymeric coating operations are commonplace in the pharmaceutical industry, film coating processes are still not fully understood, which presents serious challenges with current regulatory requirements. Novel analytical technologies and various modeling techniques that are being used to better understand film coating processes are discussed. This review article also examines the challenges of implementing process analytical technologies in coating operations, active pharmaceutical ingredients in polymer film coatings, the use of high-solids coating systems and continuous coating and other novel coating application methods.