The Developability Classification System: Application of Biopharmaceutics Concepts to Formulation Development

Abstract

A revised classification system for oral drugs was developed using the biopharmamaceutics
classification system (BCS) as a starting point. The revised system is designed to have a greater focus
on drug developability. Intestinal solubility, the compensatory nature of solubility and permeability in
the small intestine and an estimate of the particle size needed to overcome dissolution rate limited
absorption were all considered in the revised system. Thesystem was then validated by comparison
with literature on the in vivo performance of a number of test compounds. Observations on the test
compounds were consistent with the revised classification, termed the developability classification
system (DCS), showing it to be of greater value in predicting what factors are critical to invivo
performance than the widely used BCS.