This is the first installment in a series of articles that will provide an overview of an area of potential interest to the readers of Pharmaceutical Online and Outsourced Pharma. Subsequent articles will cover analytical method development and validation, solid solutions, potent compound handling, CFR Title 21 Part 11 requirements, combination devices, encapsulation technologies, PAT, and in vitro dissolution testing of solid dosage forms. Background The Biopharmaceutical Classification System (BCS) is an experimental model that measures permeability and solubility under prescribed conditions.
The original purpose of the system was to aid in the regulation of post-approval changes and generics, providing approvals based solely on in vitro data when appropriate. Importantly, the system was designed around oral drug delivery since the majority of drugs are, and remain, orally dosed. Waivers, permission to skip in vivo bioequivalence studies, are reserved for drug products that meet certain requirements around solubility and permeability and that are also rapidly dissolving.