WEEK 1: INTRODUCTION TO BIOPHARMACEUTICS & PHARMACOKINETICS

Biopharmaceutics

The science that examines the interrelationship of the physicochemical properties of the drug, the dosage form in which the drug is given, and the route of administration on the rate and extent of systemic drug absorption.

Pharmacokinetics

The study of the time course of drug movement in the body during adsorption, distribution, and elimation

Body

Kinetics means?

Pharmacokinetics

What the body does to the drug?

Pharmacology and its division

Pharmacodynamics

What the drug does to the body

Liberation

Absorption

Distribution

Metabolism

Excretion

Response

LADMER ENUMERATE

Liberation

Deliver of the active ingredient from a dosage form into solution

Drug release process

Liberation is also known as

Disintegration

Dissolution

The steps in liberation

Disintegration

This is the process of large particle broken to smaller particle

Dissolution

This is the process of solid particle converting to liquid phase

Liquid phase

It need to be _____ to absorb in the body

Dissolution

In liberation, what is the rate limiting step?

Dissolution

A process by which a chemical or drug becomes dissolved in a solvent

Disintegration

A state in which any residue of the tablet, except fragments of insoluble coating, remaining on the screen of the test apparatus in the soft mass have no palpably firm core

Parental injections (Intravenous, IM, ID, SC)

Sublingual and buccal tablets

Modified release dosage forms:

Extended-release

Delayed-release

Targeted release

Dosage forms in which liberation is altered

Catapress

Example of sublingual drug

Extended-release

This is a prolonged effect liberation dosage form

Extended-release

This dosage form makes the drug last longer

Delayed release

This dosage form is later in effect

Paracetamol

Example of a delayed release drug

Targeted release

Prolonged but localized dosage forms

Fentanyl

Example of buccal tablets Modified release

Fentanyl

This drug is used for chronic severe pain

Absorption

The process of uptake of the compound form the site of administration into the systemic circulation

Absorption

The movement of the drug from the site of application to the bloodstream

Bioavailability

First-pass effect

Absorption types

Bioavailability

A measurement of the rate and extent of systemic absorption of therapeutically active drug

Kidney

Main organ used for absorption

First-pass metabolism

First-pass effect is also called as

Injected medicine

Exception of first-pass effect

First-pass effect

A phenomenon in which a drug gets metabolized at a specific location in the body that results in a reduced concentration of the active drug upon reaching its site of action or the systemic circulation

Increased blood supply

In highly perfused is ____ blood supply

Distribution

Transfer of the drug from the blood to extravascular fluids and tissues

Distribution

The amount of blood perfusion in an area of the body also affects the rate at which the drug could be distributed there

Small intestine

Main organ for metabolism

Metabolism

Enzymatic or biochemical transformation of the drugs substance to (usually less toxic) metabolic products, which may be eliminated more readily from the body

Xenobiotics

The foreign chemicals in the body

Metabolism

Detoxification/biotransformation

Kidney

Main organ of excretion is

Excretion

Final loss of the drug substance or its metabolites from the body

Through the kidney

In excretion polar metabolites —>

Through the bile

In the excretion of non-polar drugs —->

Therapeutic effect

Sub therapeutic effect

Side effect

Toxic effect

Response refers to

Clinical pharmacokinetics

Application of pharmacokinetics method to drug therapy

Clinical pharmacokinetics

The study of the relationships between drug dosage regimens and concentration-time profiles

Clearance

Volume of distribution

Elimination half life

Three fundamental parameters

Clearance

Volume of fluid completely cleared of drug per unit time

Volume of distribution

Apparent volume into which the drug has distribution to produce the measured concentration

t1/2

Elimination half life symbol

Elimination half life

Time taken for 50% of the drug to be eliminated

Therapeutic drug monitoring (TDM)

Clinical pharmacokinetic service (CPKS)

Under the clinical pharmacokinetics

Therapeutic drug monitoring (TDM)

Employed for very potent drug to optimize efficacy and to prevent any adverse toxicity

Therapeutic drug monitoring (TDM)

Branch of clinical pharmacology that specialized in the measurement of medication levels in blood

Clinical pharmacokinetic service (CPKS)

Provides pharmacokinetic and drug analysis services for safe drug monitoring

Immunosuppression

This is the counter effect during the organ transplant for the body to accept the foreign matter

Tacrolimus

This drug clinical use is immunosuppression

Digoxin

This drug clinical use is heart failure, artrial fibrillation

Lithium

This clinical use of drug is bipolar disorder

Phenytoin

This clinical use of the drug is seizure control

Warfarin

This clinical use of drug is anticoagulation

Theophylline

The clinical use of this drug is asthma, COPD

Carbamazepine

This clinical use is epilepsy, bipolar disorder

Vancomycin

The clinical use of the drug is severe bacterial infections

Cyclosporine

The clinical use of this drug is immunosuppression post-transplant

Levothyroxine

This clinical use of this drug is hypothyroidism

Population Pharmacokinetics

Study of pharmacokinetics differenced of drugs in various population

Experimental Pharmacokinetics

Development of biological sampling techniques, analytical methods for the measurement of drugs and metabolites and procedure that facilitates data collection and manipulation

In vivo

In vitro

In silico

Types of experimental pharmacokinetics

In vivo

Involves human subjects/laboratory animal

In vitro

Employs apparatus and equipment without involving human subjects/laboratory animals

In silico

Predicted first in theories

Theoretical pharmacokinetics

Development of pharmacokinetics models that predict drug disposition after administration

Empirical

Physiological

Compartmentally based

Pharmacokinetic models different models

Model

A hypothesis using mathematical terms to describe quantitative relationship concisely

Empirical

A model in which the plasma conc, and time data are given and an equation is derived from the given data

Physiological

Describes drug movement in the body based on organ blood flow and organ spaces penetrated by the drug

Compartmentally based

A model in which organs with the same blood flow and drug affinity are grouped together

Compartment models

Hypothetical space bound by an unspecified membrane across which drugs are transferred

Catenary

Mamillary

Physiologic

Three types of compartment models

Mamillary model

One or more peripheral compartments connected to a central compartment

Mamillary model

The most common compartment models

Mamillary model

This represent plasma and highly perfused tissues which rapidly equilibrate with the drug

Catenary Model

Consists of compartments joined to one another like the compartments of a train

Physiologic pharmacokinetic model (flow model)

Considers that blood flow is responsible for distributing drugs to various parts of the body

Pharmacodynamics

The study of the relation of the drug concentration or amount at the site of action and its pharmacological response

Clinical toxicology

The study of the adverse effects of drugs and toxic substances in the body

All things are poison and nothing is without poison; only the dose makes a thing not a poison”

Paraselceus stated that?

Invasive method

Measurement of drug concentration samling of biologic specimen

Invasive method

Requires surgical/parental intervention

Sampling of blood

Spinal fluid

Synovial fluid

Tissue biopsy

Example of invasive method

Non-invasive method

Without surgical/parental intervention

Feces

Urine

Saliva

Example of non-invasive method

Blood

This is a highly specialized tissue composed of many different kinds of components

Whole blood + clot + centrifuge + supernatant

This comprises of the Serum

Whole blood + (+) heparin [anti coagulant] + centrifuge + supernatant

This comprises of plasma

Adjustment of the drug dosage in order to individualized and optimize therapeutic drug regimen

Provides guide to the progress of disease state

Enable to modify the drug dosage accordingly

What is the importance of measuring plasma drug concentration

Minimum effective concentration (MEC)

Minimum concentration needed to produce the desired pharmacologic effect

Minimum toxic concentration (MTC)

Concentration needed to just barely produce toxic effects