Bcs Class 1 Drugs
INTRODUCTION The FDA’s Biopharmaceutics Classification System(BCS) is based on the work of Amidon and coworkers with the core idea being that in vitro methodology, centrally embracing permeability and solubility, with qualifications related to pH and dissolution, may qualify drug products for a waiver of in vivo bioequivalence studies. The objective of the BCS is to predict in vivo performance of drug products from in vitro measurements of permeability and solubility. In 2005, Wu and Benet recognized that for drugs exhibiting high intestinal permeability rates the major route of elimination in humans was via metabolism, while drugs exhibiting poor intestinal permeability rates were primarily eliminated in humans as unchanged drug in the urine and bile.
They proposed that a biopharmaceutics drug disposition classification system (BDDCS) could serve as a basis for predicting the importance of transporters in determining drug disposition, as well as in predicting drug-drug interactions. The major differences between BCS and BDDCS relate to their purpose and the measurement for classification as depicted in. The purpose of BCS is to characterize drugs for which products of those drugs may be eligible for a biowaiver of in vivo bioequivalence studies. The purpose of BDDCS is to predict drug disposition and potential drug-drug interactions in the intestine and the liver, and potentially the kidney and brain. Both BCS and BDDCS use solubility as one of the two classification criteria. The solubility parameter utilized may be called the FDA solubility, that is, an estimate of the ability of the drug at its highest dose strength to completely dissolve in 250 ml of water over a pH range between 1 and 7.5 at 37°C.
Bcs Class 1 Drugs List
For a drug to be considered highly soluble in the two classification systems, the drug from its highest strength regulatory approved dosage form must go completely into solution at its lowest solubility over this pH range in 250 ml of water. As we have recently noted, FDA solubility is a property of the drug in a formulation and is not an intrinsic property of the active pharmaceutical ingredient itself. The second classification parameter, and where the two systems differ, is related to intestinal permeability. In BDDCS, predictions are based on intestinal permeability rate, which was found to be related to extent of drug metabolism.
In BCS, biowaivers are based on the extent of intestinal absorption, which in a number of cases does not correlate with intestinal permeability rate. THE BCS AND ITS USE IN DRUG DEVELOPMENT The BCS characterizes drugs into four classes according to their FDA solubility and permeability as depicted in.
Bcs Class 1 Drugs List
BCS based biowaivers are not applicable for the following: i. Narrow therapeutic range drug products. BCS based biowaivers have limited application for the class II drugs and not applicable for class III. Dosage form meant for absorption in the oral cavity e.g. Sublingual or buccal tablets.