Modern bioavailability, bioequivalence and biopharmaceutics classification system. New scientific approaches to international regulatory standards.

In the last decade, the regulatory bioequivalence (BE) requirements of drug products have undergone major changes. The introduction of the biopharmaceutics drug classification system (BCS) into the guidelines of the Food and Drug Administration (FDA) is a major step forward to classify the biopharmaceutical properties of drugs and drug products. Based on mechanistic approaches to the drug absorption and dissolution processes, the BCS enables the regulatory bodies to simplify and improve the drug approval process. The knowledge of the BCS characteristics of a drug in a formulation can also be utilized by the formulation scientist to develop a more optimized dosage form based on fundamental mechanistic, rather than empirical, information. This report gives a brief overview of the BCS and its implications.