Every time a patient takes a medicine, a precise sequence of events begins inside the body — the drug is absorbed, distributed to target tissues, metabolised, and finally excreted. Biopharmaceutics and Pharmacokinetics — commonly called BPK among B Pharma students — is the subject that explains and mathematically models this entire journey. Biopharmaceutics focuses on how a drug’s physical and chemical properties affect its absorption. Pharmacokinetics gives you the equations and models — one-compartment, two-compartment, nonlinear — to predict, calculate, and optimise drug behaviour over time.
These BPK notes are prepared as per the PCI-approved B Pharma 6th semester syllabus 2025–26, structured unit-wise from drug absorption and ADME fundamentals all the way to Michaelis-Menten nonlinear kinetics. Each unit download includes a clear topic summary so you know exactly what is inside before opening the PDF. BPK is one of the most numerically intensive and GPAT-heavy subjects in B Pharma — pharmacokinetic parameters, bioavailability calculations, half-life, AUC, and compartment models appear in almost every GPAT paper. These notes include key equations and step-by-step calculation methods alongside theory.
Download Biopharmaceutics and Pharmacokinetics Notes in PDF – Unit Wise
Click below to download free PDFs for each unit:
Course Units
Unit 1: Drug Absorption & Distribution in Biopharmaceutics
Topics Covered: Mechanisms and factors affecting drug absorption via gastrointestinal and extravascular routes, along with drug distribution, protein binding, volume of distribution, and their clinical significance.
Unit 2: Drug Elimination, Bioavailability & Bioequivalence
Topics Covered: Includes drug metabolism and excretion pathways, renal and non-renal clearance, principles of bioavailability and bioequivalence, in-vitro–in-vivo correlation, and strategies to improve drug dissolution and absorption.
Unit 3: Pharmacokinetic Models & Parameters
Topics Covered: Fundamental pharmacokinetic concepts, compartment and non-compartment models, drug administration routes, and key parameters such as half-life, clearance, volume of distribution, and AUC with clinical applications.
Unit 4: Multicompartment & Multiple Dose Pharmacokinetics
Topics Covered: Explains two-compartment open models, intravenous bolus kinetics, steady-state drug levels, and calculation of loading and maintenance doses for optimal therapy.
Unit 5: Nonlinear Pharmacokinetics
Topics Covered: The principles of nonlinear pharmacokinetics, causes of non-linearity, and Michaelis–Menten kinetics for estimating pharmacokinetic parameters with drug examples.
What is Biopharmaceutics and Pharmacokinetics?
Biopharmaceutics and Pharmacokinetics is a vital pharmaceutical subject that explains how a drug behaves inside the body and how the body, in turn, affects the drug. It connects formulation science with clinical outcomes by showing how factors like dosage form, route of administration, and physiology influence drug action.
Instead of focusing only on drug composition, this subject helps you understand the journey of a drug from administration to elimination, making it essential for designing effective and safe therapies.
These notes will help you grasp important concepts such as:
- Introduction to Biopharmaceutics
Understanding the relationship between drug formulation and its availability at the site of action. - Drug Absorption Mechanisms
How drugs cross biological membranes and the factors affecting their absorption in the body. - Distribution of Drugs
Movement of drugs through blood and tissues, including protein binding and tissue affinity. - Drug Metabolism (Biotransformation)
Chemical changes drugs undergo in the body, mainly in the liver, affecting their activity and duration. - Drug Excretion
Elimination of drugs through kidneys and other routes, influencing drug clearance. - Pharmacokinetic Models
Study of compartment models and how drug concentration changes over time. - Bioavailability and Bioequivalence
Measuring the extent and rate at which a drug reaches systemic circulation and comparing different formulations. - Dosage Regimen Design
Understanding half-life, clearance, and volume of distribution to determine appropriate dosing schedules.
Frequently Asked Questions (FAQ)
Q1. What is the difference between biopharmaceutics and pharmacokinetics?
Biopharmaceutics studies how a drug’s physicochemical properties and dosage form affect its absorption into the body. Pharmacokinetics studies what the body does to the drug after absorption — how it is distributed, metabolised, and excreted, using mathematical models and equations to quantify these processes.
Q2. What is ADME in pharmacokinetics?
ADME stands for Absorption, Distribution, Metabolism, and Excretion — the four fundamental processes that determine a drug’s concentration and effect in the body over time. These form the core of both biopharmaceutics and pharmacokinetics, covered in Units 1 and 2.
Q3. What is bioavailability and why is it important?
Bioavailability is the fraction of an administered drug dose that reaches systemic circulation in unchanged form. It is critical because it determines how much of the dose actually reaches the target site. Absolute bioavailability compares a drug formulation against intravenous administration; relative bioavailability compares two non-IV formulations.
Q4. What is a one-compartment pharmacokinetic model?
The one-compartment model assumes the body acts as a single homogeneous compartment where the drug distributes instantly and uniformly. It is the simplest PK model and is used when drug concentration in plasma declines in a single log-linear phase after administration. Covered in detail in Unit 3.