BiopharmaceuticsMany factors have b

BiopharmaceuticsMany factors have been found to influence the time course of a drug in the plasma and hence at its site(s) of action. These include the foods eaten by the patient, the effect of the disease state on drug absorption, the age of the patient, the site(s) of absorption of the administered drug, the coadministration of other drugs, the physical and chemical properties of the administered drug, the type of dosage form, the composition and method of manufacture of the dosage form and the size of dose and frequency of administration of the dosage form. Thus, a given drug may exhibitdifferences in its bioavailability if it is administered in the same type of dosage form by different routes of administration, e.g. an aqueous solution of a given drug administered by the oral and intramuscular routes of administration. A given drug may also show differences in its bioavailability from one type of dosage form to another when given by the same route, e.g. a tablet, a hard gelatin capsule and an aqueous suspension administered by the peroral route. A given drug might show different bioavailabilities from different formulations of the same type of dosage form given by the same route of administration, e.g. different formulations of an aqueous suspension of a given drug administered by the peroral route. Variability in the bioavailability exhibited by a given drug from different formulations of the same type of dosage form or from different types o