Pharmacology is the study of drugs and their interaction with living systems. A drug is a chemical substance used for medical purposes like treating disease, while a medicine contains one or more drugs along with other ingredients to make it easier to use therapeutically. Pharmacology emerged in the mid-19th century based on earlier traditions of using plants, animals and minerals for medicine, though historically there was little scientific understanding of how treatments worked. Some of the earliest written records of pharmacology include the Chinese book Pen T'sao from 2735 BC describing 365 medicinal plants, the 2500 BC Ayurvedic manuscript Dravyaguna on herbal medicine in India, and Sumerian clay tablets from 2100 BC with drug preparation recipes

2. What is pharmacology?
 Derived from Greek word.
 PHARMAKON (a drug or medicine) and LOGOS (study).
 Science that deals with drugs.
What is a drug?
 Derived from a French word.
 DOGUE means ‘dry herbs.
 Chemical substances used for the diagnoses, prevention or treatment of the disease.
What is a medicine?
 Chemical preparation.
 Usually contains one or more drug, administered with the intention of producing a therapeutic effect.
 Contains Excipients besides active drug to make them more convenient to use.

3. History
Introduction:
 Born as a science – mid 19th century.
 Long before that – use of natural substances e.g. Plants, animals, minerals. (some are still used today)
 But no scientific basis.
 Homeopathy (similar sufferings).
 Allopathy (other sufferings).
Reasons of failure:
 Poor knowledge of functioning of the body.
 Lack of experimentation and observation.
Materia medica:
 Precursor to pharmacology.
 Later on pharmacology emerged as its own discipline in 19th century.

4. Historical sources
PEN T’SAO (2735 BC):
 Chinese book on root and grasses.
 Written by Emperor Shen Nung circa.
 Treats 365 dugs (dried parts of medicinal plants).
DRAVYAGUNA (2500 BC):
 Ayurvedic manuscript (India) of Materia medica (medicinal material).
 The science of life.
 Includes sources, descriptions, criteria for identification, properties, methods for preparation and
therapeutic uses of hundreds of medicinal herbs.
SUMERIAN (2100 BC):
 Clay slab from Nagpur
 Approximately 5000 years old.
 Comprised 12 recipes for drug preparation referring to over 250 various plants.

5. EGYPTIAN (1500-1900 BC):
1. Ebers Papyrus:
 Egyptian Materia medica.
 800 prescriptions.
 Recipes for treatment of diseases.
2. George Ebers:
 700 herbal prescriptions, including opium.
BABYLONIAN (700 BC):
 Clay tablet.
 Mention about 300 drugs.