Generic drug products bioavailability-bioequivalency

SCIENTIFIC BASIS FOR GENERIC DRUG PRODUCT EQUIVALENCY BIOAVAILABILITY-BIOEQUIVALENCY... 

The topic of generic bioequivalence pertains to the relative bioavailability of different versions of the same drug product, all of which may be available in the marketplace at the same time. Thus, if we continue our consideration of the example introduced in the previous section of this chapter, let us suppose that the innovator did obtain approval to market F3. Initially F3 was the only product available in the marketplace. However, when the relevant patents held by the innovator have expired, other pharmaceutical... 

The other computation is that of relative bioavailability. This calculation is determined when two products are compared to each other, not to an intravenous standard. This is commonly calculated in the generic drug industry to determine that the generic formulation (e.g., a tablet) is bioequivalent to the original formulation (e.g., another tablet). Thus, bioavailability is not routinely calculated in an individual patient but reserved for product development by a drug manufacturer. However, it is important to have an idea of how formulations or routes of administration differ with respect to bioavailability so as to allow proper dosage adjustment when changing formulations or routes of administration. 

Christians U, First MR, Benet LZ (2000) Recommendations for bioequivalence testing of cyclosporine generics revisited. Ther Drug Monit 22 330-335 CPMP (2000) European Medicines Agency. Committee for Proprietary Medicinal Products. Note for guidance on the investigation on bioavailability and bioequivalence. CPMP/EWP/QWP/1401/98.http //www.emea.europa.eu/pdfs/human/qwp/140198en.pdf. Cited 30 Dec 2008... 

Bioequivalence Scientific basis on which generic and brand-name drugs are compared. To be considered bioequivalent, the bioavailability of two products must not differ significantly when the two products are given in studies at the same dosage under similar conditions. Some drugs, however, are intended to have a different absorption rate. The FDA may consider a product bioequivalent to a... 

The goal of the testing of generic products is not to establish the clinical usefulness of the drug but only to ensure that the generic product or new formulation has the same relative bioavailability as or is bioequivalent to the innovator product. 

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