Biopharmaceutics Classification System 4248332 220741899 2008-06-21T10:37:52Z Eubot 231599 Hatnote formatting, see [[User:Eubot/Hatnote formatting]] {{for|other uses of the abbreviation '''BCS'''|BCS (disambiguation)}} The '''Biopharmaceutics Classification System''' is a guidance for predicting the [[gastrointestinal tract|intestinal]] [[drug]] absorption provided by the [[U.S. Food and Drug Administration ]][http://www.fda.gov/]. The fundamental basis for the BCS was established by Dr. Gordon Amidon who was presented with a Distinguished Science Award at the August 2006 International Pharmaceutical Federation (FIP) congress in Salvador, Brazil.{{Fact|date=February 2007}} This system allows to restrict the prediction using the parameters [[solubility]] and [[intestinal permeability]]. The [[solubility]] classification is based on a [[United States Pharmacopoeia]] (USP) apperature. The [[intestinal permeability]] classification is based on a comparison to the [[Route of administration|intravenous injection]]. All those factors are highly important, since 85% of the most sold drugs in the [[USA]] and [[Europe]] are [[route of administration|orally administered]]. According to the Biopharmaceutics Classification System ([[BCS (disambiguation)]]), drug substances are classified as follows: *'''Class I - High [[intestinal permeability|Permeability]], High [[Solubility]] ''' ** Example: [[Metoprolol]] ** Those compounds are well absorbed and their absorption rate is usually higher than excretion. *'''Class II - High [[intestinal permeability|Permeability]], Low [[Solubility]] ''' ** Example: [[Glibenclamide]] ** The [[bioavailability]] of those products is limited by their solvation rate. A correlation between the [[in vivo]] [[bioavailability]] and the [[in vitro]] solvation can be found. *'''Class III - Low [[intestinal permeability|Permeability]], High [[Solubility]] ''' ** Example: [[Cimetidine]] ** The absorption is limited by the permeation rate but the drug is solvated very fast. If the formulation does not change the permeability or gastro-intestinal duration time, then class I criteria can be applied. *'''Class IV - Low [[intestinal permeability|Permeability]], Low [[Solubility]] ''' ** Example: [[Hydrochlorothiazide]] ** Those compounds have a poor [[bioavailability]]. Usually they are not well absorbed over the intestinal mucosa and a high variability is expected. ==See also== *[[ADME]] **[[Partition coefficient]] **[[Bioavailability]] **[[Drug metabolism]] **[[First pass effect]] *[[Polar surface area]] ==References== * H. Waterbeemd, H. Lennernäs, P. Artursson (editors), ''Drug bioavailability: estimation of solubility, permeability, absorption and bioavailability'', Wiley-VCH, Weinheim, Germany, '''2003'''. ISBN 3-527-30438-X ==External links== * [http://www.fda.gov/cder/OPS/BCS_guidance.htm BCS guidance] of the [[U.S. Food and Drug Administration]] {{pharma-stub}} [[Category:Pharmacology]] [[Category:Pharmacy]]