This document outlines the curriculum for a pharmacology lab course focused on bioassays, including definitions, methods, and applications. It details experiments and demonstrations involving drug effects on various biological models, as well as toxicity studies in compliance with ethical guidelines. The course aims to enhance understanding of drug potency, biological activity, and the drug discovery process.

1. AIM:
Introduction to Pharmacology lab II
Presented by:
Prof. Mirza Anwar Baig
Dept of Pharmcaology
AIKTC, School of Pharmacy, New Panvel

2. Course outcomes:
1. Define Bioassay, list the types, methods and applications of
bioassay and perform in vitro bioassay using cock ileum and
record, calculate and interpret unknown concentration of
agonist/antagonist/drug.
2. Observe preclinical models which provide evidences on drug/lead
pharmacological activity.
3. Relate to and apply the ethical, regulatory and toxicity
guidelines/rules (ICH, OECD, CPCSEA, Schedule Y) in drug/lead
testing using preclinical animals

3. Syllabus
No. Details
1. Experiments:
1. Bioassay of Acetylcholine using suitable isolated tissue preparation e.g. Cock
ileum
2. Bioassay of Atropine using suitable isolated tissue preparation e.g. Cock ileum
2. Demonstrations: (with kymograph recordings or audio-visual aids)
1. Bioassay of oxytocin
2. Behavioral Pharmacology Demonstrations/ Simulated experiments (CDs).
• • To study effect of drugs on locomotor activity in rodents using
actophotometer.
• • To study the muscle relaxant property of drug using Rota-rod.
• • To study analgesic activity of drug using an analgesiometer.
• • To study anticonvulsant activity of drugs using maximal electroshock/
chemically induced seizures.
• • To study phenothiazines induced catalepsy using suitable animal model.
3. Toxicity studies
• Introduction to CPCSEA, OECD guidelines
• Introduction to acute, sub-acute and chronic toxicity studies

4. INTRODUCTION TO BIOASSAYS
• Procedures by which the potency or the nature of the substance
(constitution) is estimated by studying its effects on living matter.
• Bioassays are generally done using animal tissues or organs
Example:
Guinea pig ileum for the estimation of histamine or using the intact animal
Bioassay of insulin using mouse or digitalis bioassays using guinea pigs.

5. Bioassays procedures are generally employed:
(1) When a chemical assay for the substance is not available or the substance
gets inactivated by interacting with chemicals as the case with hormones;
(2) When the quantity of the sample is too small. In such situation a matching
type of bioassay is conveniently done to compare the biological response
with the standard drug;
(3) To estimate the concentrations of active principles present in the tissue
extracts, the endogenous mediators like acetylcholine, 5-HT,
prostaglandins;
(4) To measure the pharmacological activity of new or chemically unidentified
substance;
(5) To measure drug toxicity; and
(6) When the bioassay is more sensitive than the chemical assay.

6. Advantages:
1. Essential in the development of new drugs.
2. In the preclinical assessment of a new compound, the biological activity is
compared with that of known (standard) compound(s) using appropriate
test systems.
3. In such studies the tests must be simple, reproducible and economical.
4. Biological assessment of a new compound generally consists of carrying
out a battery of such assays and based on these tests, constructing a profile
of activity.
5. Clinical testing of drugs is guided by such a profile of activity generated
in animals.

7. Drug Discovery Process

8. Use of standards
• Biological assays are designed to measure relative potency of two
preparations (standard and an unknown).
• The standard substance is a pure substance and, in official bioassays it
refers to pharmacopoeia standards.
• Standard substance helps in solving problems arising from biological
variations.
• The observed response/ effect of the unknown would be always relative to
the effect that produced by a standard substance.

9. Types of bioassays:
1. Bioassays are of two types namely, quantal and graded.
2. The quantal assay is an “all or none”phenomenon. For example, insulin-
induced hypoglycemic convulsive reaction or the cardiac arrest caused by
digitalis.
3. The graded response assays are based on the observations that there is a
proportionate increase in the observed response with a subsequent
increase in the concentration and dose.
4. The choice of the procedure depends on the (1) precision of assay
demands; (2) quantity of the sample available; and (3) availability of
experimental animals

10. Types of bioassay
(a) Matching bioassay
(b) Interpolation method
(c) Bracketing method
(d) Multiple point bioassay
– Three point bioassay,
– Four point assay,
– Six-point bioassay,

11. ERRORS IN IN-VITRO BIOASSAY:-
The factors contributing to error in bioassay are:-
(i) Syringe
(ii) Unstable baseline
(iii) Spontaneous mobility of the tissue
(iv) Temperature and volume of the bath
(v) Erratic response

12. References:
1. Kulkarni S. K. Handbook of Experimental
Pharmacology, Vallabh Prakashan, New Delhi.
2. Ghosh M.N. Fundamentals of Experimental
Pharmacology Hilton & Company, Kolkata

13. Thank You