Absorption of drugs
Absorption is defined as the movement of drug from the site of administration to the target site, through the bloodstream. The three main factors effecting the rate and extent at which a drug is absorbed include the environment of the absorption site, chemical composition of drug and the route through which the drug is administered. Mechanism of drug absorption Drugs are absorbed from the Gastrointestinal Tract through a number of ways. These include diffusion(passive and facilitated), active transport or endocytosis. Passive diffusion Passive diffusion is carried out due to development of concentration gradient across a membrane. The drugs moves from the compartment having the higher concentration of drug to the one having the lower concentration. Passive diffusion does not requires the presence of a carrier. A large number of drugs are absorbed via passive diffusion. The water soluble drug components diffuse through aqueous channels whereas the lipid soluble drug...