Vol. 2, Issue 5 (2013)

Author(s):
K.P. Sampath Kumar*, Debjit bhowmik, J. preethi, S. Duraivel, Rajnesh kumar Singh

Abstract:
Bioavailability is used to describe the fraction of an administered dose of medication that reaches the systemic circulation, one of the principal properties of the drugs. By definition, when the drug is administered intravenously, its bioavailability is 100%. However when a medication is administered via other routes (such as oral), its bioavailability decreases (due to incomplete absorption and first-pass metabolism). Bioavailability is one of the essential tools in pharmacokinetics, as bioavailability must be considered when calculating dosages for non-intravenous routes of administration. “The rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action. For the drug products which are not intended to be absorbed into the bloodstream, bioavailability may be assessed by measurements intended to reflect the rate and extent to which the active ingredient or active moiety becomes available at the site of action.