BP604T. BIOPHARMACEUTICS AND PHARMACOKINETICS (Theory)

Unit-I

Introduction to Biopharmaceutics:

• Absorption:
• Mechanisms of drug absorption through the gastrointestinal tract (GIT).
• Factors influencing drug absorption (physicochemical, physiological, and formulation factors).
• Absorption from non-peroral routes (e.g., transdermal, nasal, pulmonary).
• Distribution:
• Tissue permeability of drugs.
• Drug binding to plasma and tissue proteins.
• Apparent volume of distribution (Vd).
• Factors affecting drug distribution.

Unit-II

Elimination:

• Drug Metabolism:
• Phase I and Phase II metabolic pathways.
• Factors affecting drug metabolism (age, genetics, disease states).
• Excretion:
• Renal excretion: Mechanisms, renal clearance, and factors affecting excretion.
• Non-renal routes of excretion (biliary, pulmonary, salivary, etc.).
• Bioavailability and Bioequivalence:
• Definitions and objectives.
• Absolute and relative bioavailability.
• Methods to measure bioavailability.
• In-vitro-in-vivo correlations (IVIVC).
• Bioequivalence studies and regulatory requirements.

Unit-III

Pharmacokinetics:

• Basic Concepts:
• Definition and importance of pharmacokinetics.
• Compartment models (one-compartment, two-compartment).
• Non-compartmental and physiological models.
• One-Compartment Open Model:
• Intravenous bolus, intravenous infusion, and extravascular administration.
• Pharmacokinetic parameters: Elimination rate constant (Ke), half-life (t1/2), volume of distribution (Vd), area under the curve (AUC), absorption rate constant (Ka), total clearance (Clt), and renal clearance (ClR).

Unit-IV

Multicompartment Models:

• Two-Compartment Open Model:
• Kinetics of drug distribution and elimination.
• Multiple Dosing:
• Steady-state drug levels.
• Calculation of loading and maintenance doses.
• Clinical significance of multiple dosing regimens.

Unit-V

Nonlinear Pharmacokinetics:

• Introduction:
• Causes of nonlinearity (saturation of enzymes, transporters, etc.).
• Michaelis-Menten kinetics: Estimation of parameters (Vmax, Km).
• Examples of drugs exhibiting nonlinear pharmacokinetics.
• Applications of Pharmacokinetics:
• Individualization of drug therapy.
• Optimization of dosing regimens.
• Therapeutic drug monitoring (TDM).