ABSTRACT
Absorption, Distribution, Metabolism and Excretion is the pharmacokinetic study of the drugs. Prodrugs are pharmacologically inactive molecules which are converted to active molecule under in vivo biotransformation by enzymatic or chemical reactions. The molecules that have poor physiochemical, biopharmaceutical or pharmacokinetic properties are generally converted into prodrug. The inactive moiety of the ideal prodrug should be nontoxic and excreted out rapidly from the body. A good prodrug should contain number of characteristics such as partial P-glycoprotein efflux, ability to hydrolyze in the GI lumen and intestinal cells, biliary excretion, nonesterase metabolism in the liver and transformation of the parent moiety. Various types of pharmacokinetic models are used to describe drug absorption, distribution, metabolism, and elimination from the body. The one-compartment open model is the simplest mammillary model that describes drug distribution and elimination. The drug equilibrates rapidly in the body, and it is assumed that the concentration throughout the compartment is equal to the plasma concentration.
