Biopharmaceutics and Pharmacokinetics Overview

Biopharmaceutics

• Biopharmaceutics is the science studying the relationship between drug properties, dosage form, and route of administration on the rate and extent of drug absorption.
• It considers factors like drug stability within the product, release from the product, dissolution/release rate at absorption site, and systemic absorption.

Pharmacokinetics

• Pharmacokinetics is the study of how the body handles drugs including drug absorption, distribution, and elimination (excretion and metabolism).
• Drug movement in the body can be described by mathematical models and statistics.
• The study uses both experimental and theoretical approaches. Experimental aspect involves developing biological sampling techniques, analytical measurement methods for drugs and metabolites, and data collection/manipulation.
• Theoretical aspect involves creating pharmacokinetic models for drug disposition post-administration.
• Statistics are crucial to determine optimal dosing regimens for individuals or groups.

Clinical Pharmacokinetics

• Optimized dosing regimens are determined through studies in large numbers of patients.
• Variations in individual patients may lead to subtherapeutic or toxic responses, necessitating dose adjustments.
• Clinical pharmacokinetics focuses on applying pharmacokinetic methods to drug therapy using a multidisciplinary approach.
• It involves patient-specific dosing strategies based on disease state and individual considerations.
• Factors like age, gender, genetics, and ethnicity affect pharmacokinetics.
• The study of these population variations is termed "population pharmacokinetics."

Pharmacodynamics

• Pharmacodynamics examines the relationship between drug concentration at the receptor site and the resulting pharmacological/toxic response.
• This includes biochemical and physiological effects that influence drug-receptor interaction.
• Drug-receptor interaction initiates molecular events leading to a pharmacological/toxic response.
• Pharmacokinetic-pharmacodynamic models relate plasma drug levels to drug concentration at the site of action.
• These models can determine intensity and time course of the drug.

Toxicokinetics

• Toxicokinetics applies pharmacokinetic principles to drug safety evaluations, validating dose-related exposure, and interpreting animal data for human use.
• It's used in preclinical drug development to assess toxicologic findings in animals.
• Toxicokinetic studies may continue after clinical trials.

Clinical Toxicology

• Clinical toxicology studies adverse effects of drugs and toxic substances (poisons).
• The pharmacokinetics in overmedicated (intoxicated) individuals can differ greatly from normal use.
• High doses can saturate enzymes involved in absorption, biotransformation, or renal secretion, shifting pharmacokinetics from linear to non-linear.

Contents

• The course covers topics such as Biopharmaceutics, Pharmacokinetics, Clinical Pharmacokinetics, Pharmacodynamics, Toxicokinetics, Measurement of drug concentrations, Sampling of biological specimens, drug concentrations in blood/plasma/serum, plasma level-time curves, Generics and brands, Generic equivalence, Therapeutic equivalence, Bioavailability, Bioequivalence, Pharmacokinetics and its parameters, Protein Binding.
• In-vitro methods, In-vivo methods also feature in the course.