This workshop was held at the Society Hall of the Royal Pharmaceutical Society in London on 8-9th October 2001 under the auspices of the International Pharmaceutical Federation (FIP) and the Academy of Pharmaceutical Sciences (APS), of Great Britain.ĭr. To-date, however, only drug products which fall in the Class 1 category, which contain highly soluble, highly permeable drug substances in IR solid oral dosage forms that exhibit rapid According to the BCS, when certain criteria are met, the classification system can be used as a drug development tool to assess bioequivalence In addition, IR dosage forms are categorized as having rapid or slow dissolution. When combined with the dissolution of a drug product, the BCS takes into account 3 major factors which govern the rate and extent of drug absorption from immediate release (IR) solid oral dosage forms (tablets/capsules), viz: dissolution rate, solubility and permeability.Īccording to the BCS, drug substances are classified as follows:Ĭlass 1: High solubility-High permeabilityĬlass 2: Low solubility-High permeabilityĬlass 3: High solubility-Low permeability The BCS is a scientific framework for classifying drug substances based upon their aqueous solubility and intestinal permeability.
THE BIOPHARMACEUTICS CLASSIFICATION SYSTEM (BCS) Considerations of drug solubility and permeability are additional drug properties which influence product performance, both of which can be assessed However, only when dissolution is the rate-limiting step will the measurement of dissolution rate provide useful information on drug product performance. Hence the dissolution rate of dosage forms is one of several factors which can account for differences in performance between drug products administered in the same dosage form and same strength containing the same active ingredient. This is based on the premise that in order to elicit a response, the active ingredient in a dosage form must be released and subsequently dissolve in biological fluids in order to move to and become available at the site of action in the body. Methods, such as dissolution rate determinations in particular, have been considered as potential models to predict Studies involve the use of healthy human subjects and various
Comparative bioavailability studies between test and reference product involve the assessment of bioequivalence between a generic and innovator product in order to confirm the absence of a significant difference in the rate and extent to which the active ingredient or active moiety in pharmaceutically equivalent dosage forms becomes available at the site of action when administered at the same molar dose under similar conditions in an appropriately designed study in human subjects. Since the reference product would have been approved on the basis of clinical trials where the safety and efficacy of that product was established, the need to redo expensive and time consuming clinical trials to assess the safety and efficacy is considered unnecessary and instead, a surrogate measure whereby the concentration of drug in serum/plasma of human subjects is compared between the test and reference product is considered more appropriate. The assessment of the safety and efficacy of multisource (generic) products involves a comparative study between the generic (test) products to be registered versus the innovator (reference) where their respective bioavailabilities are compared.
0 kommentar(er)
