This document defines drugs and classifies them according to their source and nature. It states that drugs are substances used for disease diagnosis, prevention and treatment. Drugs are classified as plants, animals, minerals, microorganisms, semi-synthetic and synthetic based on their source. Based on their nature, drugs contain active constituents like alkaloids, glycosides, oils, tannins, gums, resins, antibiotics and hormones. Examples of each type of drug are provided.

1. Prepared by
Ms. Nisha S. Mhaske
M.Pharm (Q.A.T)
Lecturer, PRES’s COPD, Chincholi.
Email : nisha.mhaske@pravara.in

2. What is Drug?????
Drug is derived
from French word
‘Drogue’ meaning
Dry Herb.
Drug is defined as
any substance used
for diagnosis,
prevention &
treatment of
disease.

3. Classification of
drugs
As per source of drugs As per nature of drugs
Plants Alkaloids
Animals Glycosides
Minerals Oils- Volatile oil, Fixed oil
Micro-organism Tannins
Semi-synthetic Gums
Synthetic Resins
Antibiotic
Hormones

4.  Plants
 Eg- Morphine, digoxin, reserpine, vinblastin
 Digitalis- Digoxin- cardiac glycoside
 Poppy capsule- Opium- Narcotic
 Cinchona Bark-Quinine- Antimalarial.
 Animals
 Liver, endocrine glands & secretary organs of animals are used
to extract active constituent.
 Eg- Liver extract, Insulin,
 Thyroid extract- thyroxine.
 Heparin-obtained from cow lungs, pig intestine - used as anti
coagulant (Blood Thinner)
 Heparin- occurring in mixture of Mucopolysaccharide i.e.
Present in the human body in tissues of the liver & lungs.
As per Source of Drugs

5. Minerals
 It comprises of metal & non-metal with their
salts, mineral acids etc.
 Eg- Iron, zinc, aluminum, mercury, liquid
paraffin, magnesium sulphate, kaolin.
Micro-organisms
 The substance isolated from micro-organism
are used in high dilution to kill or prevent
growth of other microorganisms are called
antibiotics.
 Eg- penicillins, tetracycline, streptomycin.

6.  Semi-synthetic
 The substance obtained by chemical
modification of the naturally occurring
compounds.
 Eg- Homatropine From atropine
 Heroin from morphine
 Methyl scopolamine bromide from scopolamine
 Synthetic
 These are synthesized by chemical processes.
 Eg-Aspirin, sulphonamide, corticosteroids.

7. As per nature of drugs
 The drugs from plant origin contain
pharmacologically active constituents such as
follows:-
 Alkaloids
 These are basic nitrogenous compound.
 Conatin C,H,O & N. also some alkaloid may
contain S & P.
 Eg- Quinoline---Quinine, quinidine
 Isoquinoline---Papaverine, emetine
 Indole---Reserpine, eserine
 Imidazole---Pilocarpine

8.  Glycosides
 Thses are having organic nature
 Conatins C,H,O & some having S & N sugar
moiety.
 Eg-Digoxin, Strophanthin.
Glycoside Aglycone + Sugar moiety
 Aglycone (Genin)- non-carbohydrate residue-
pharmacologically active ingredient
 Sugar Moiety- increase penetrations & duration
of action.
Hydrolysis

9. Oils
Volatile oils Fixed oils
Imparts as aroma to a plant
and are volatilized by heat.
Which remains solid at
ordinary temperature
They evaporate and leave
no greasy stain
Eg-Olive oil, castor oil,
cod-liver oill, peanut oil.
Flavoring agent
Eg- clove oil, eucalyptus
oil, turpentine oil (Pine
wood-Devdar)

10.  Tannins
 These are non-nitrogenous plant constituents
 These are having an astringent action.
 Eg- Catechol- occur in catechu & eucalyptus (used to
treat burns & diarrhea)
 Gums
 These are chemically polysaccharides which on
hydrolysis converts into simple sugar.
 Eg- agar, acacia, tragacanth.
Gums Simple Sugar.
Hydrolysi
s

11.  Resins
 Found in plants
 Produced by oxidation and polymerization of volatile oils.
 Eg- podophyllum resins (irritant purgatives action)
 Antibiotic
 These are the chemical substances produced by various
species of micro-organisms, having the property of
inhibiting the growth or destroying the micro-organisms in
high dilution.
Bactericidal Bacteriostatic
Kill the growth of micro-
organism
Stop the growth of micro-
organism

12.  Hormones
 They are specialized chemicals generally
derived from animals, endocrine glands.
 Eg- insulin- polypeptide nature produced by
Beta cells (β cells) islets of langerhans-
Pancreas. Used to reduced elevated blood
sugar level.
 Sex hormones, corticosteroids- steroids.