Biopharmaceutics explore the interrelationship of the physical/chemical properties of the drug, the dosage form (drug product) in which the drug is given, and the route of administration on the rate and extent of systemic drug absorption and the use of this information to optimise the therapeutic efficacy of the drug products. The process of movement of drug from its site of administration to the systemic circulation is called as absorption. The concentration of drug in plasma and hence the onset of action, and the intensity and duration of response depend upon the bioavailability of drug from its dosage form. Bioavailability is defined as the rate and extent (amount) of drug absorption. Any alteration in the drug’s bioavailability is reflected in its pharmacological effects. Other processes that play a role in the therapeutic activity of a drug are distribution and elimination.
- Pharmacodynamics of drugs
- Pharmacokinetics of drugs