There are following methods of classification.
1. Alphabetic method of classification
2. Chemical method of classification.
3. Pharmacological method of classification.
4. Morphological method of classification.
5. Taxonomical method of classification.
6. Chemo- taxonomical method of classification.
1. Alphabetic Method of Classification
In this method drugs are classified according to first alphabet of their English or Latin name. This method is adopted in many books like I. P. (Indian Pharmacopoeia) N.P. (National formulary) U.S (United states Pharmacopoeia), B.P. In I.P.1955 drugs where given according to Latin name. In I. P. 1966 names changed in to English.
Amylum Changed in to starch
Acacia changed in to Indian gum.
Advantages: -If we know the name of drug, we can study it properly.
2. Chemical Method of Classification: -
Drugs are classified according to their active chemical constituent. Drugs which
Contain similar chemical are grouped in one place.
| Chamical Content | Drugs |
| 1. Volatile oil 2. Alkaloid 3.Glycoside 4.Fixed oil& fat 5. Carbohydrates 6.Vitamins 7. Lipid | Fennel oil, coriander. Rauwolfia, Datura Nuxvomica, Cinchona,and Vinca Senna leaf, Digitalis. Arachis oil, sesame oil, castor oil Acacia, Honey, starch, Isapgol Shark liver oil, cod liver oil wheat, Germ oil, Amla. Castor oil, peanut oil, mustard, and wool fat |
Disadvantages: -
1. This method does not give any idea about source of drug.
2. Some drugs contain two important chemicals so it is difficult to classify them.
e. g. Nutmeg contains volatile oil as well as fat. Cinchona contains glycoside
as well as alkaloid.
3. No idea whether drug is organized or unorganized.
Advantages: -
If we know chemical constituent. It is easy to study the drug.
Pharmacological Classification: -
The drugs having similar pharmacological effect in body are grouped together.
| Pharmacological Action | Drug |
| 1. Carminatives | Fennel, Dill, Coriander, and Clove. |
| 2. Purgatives | Cascara- sagrada, Aloe, Senna, and Rhubarb. |
| 3. Cardio tonics | Digitalis, squill, and strophanthus |
| 4. Anthelmintic | Artemisia, Male- fern, and Quassia |
| 5. Anti- cancer | Podophyllum, Vinca |
| 6. CNS Stimulant | Nuxvomica |
| 7. Expectorant | Vasaka, Liquoric |
| 8. Bitter tonic | Gentian, Cinchona, and Nux vomica |
Disadvantages: -
1. Some crude drugs have two different pharmacological actions therefore it is difficult to classify them. E.g. Nux- vomica is CNS stimulant as well as bitter tonic. Cinchona is bitter tonic as well as Antimalarial & Antipyretic.
2. Drugs that have different mechanism of action have to be grouped together.
e. g. Castor oil is irritant purgative & Isapgol is bulk purgative but they are placed in one group.
3. No idea whether drugs are organized or unorganized
4. This method does not give any idea of source of drugs.
Advantages: -
If we know pharmacological action it is easy to study the drug.
Morphological Classification: -
In this method drugs are divided into parts of plants like, Roots, Flowers, Leaves, Wood, Extracts, Gum, Bark.
| Part of Plant | Drugs |
| Fruit: | Caraway, Fennel, |
| Seed: | Nuxvomica, Nutmeg, colchicum |
| Bark: | Arjuna, Cinchona, cinnamon |
| Gum: | Acacia, Tragacanth, Streculia, and Guargum |
| Latex: | Opium, Papaya |
| Extract: | Catechu, Agar, and gelatin. |
| Leaf: | Coca, Digitalis, Senna, and Vasaka. |
Advantages: -
1. It is more convenient for practical purpose.
2. Even if the chemical content or action of drug is not known the drug can be studied properly.
3. It gives idea about source of drugs
4. It gives idea whether it is organized / unorganized.
Disadvantages: -
During collection, drying & packing morphology of drug changes. They are difficult to study.
Taxonomical Classification: -
It is purely biological classification. Drugs are given according to position of plant in plant kingdom. It is difficult system.
Disadvantage: -
No idea about organized / unorganized.
Fennel: -
Division - Angiosperm.
Class - Dicotyledonae
Order - Umbelliflorae.
Family - Umbelliferae.
Example - Fennel.
Chemo taxonomical: -
This is recent type of classification in which equal importances have been given to family of plant & it's chemical constituents. It has been found that there is closed relationship between chemical composition of the plant and its position in plant kingdom.
Ex. plants of Umbeliferae contain volatile oil, plants of Solanaceae, Apocyanaceae contain alkaloid.
- Pharmacognosy is defined as scientific & systematic study of structural, physical, chemical & biological characters of crude drugs along with history, method of cultivation, collection & preparation for the market.
- Crude Drugs: - Crude drugs are the drugs, which are obtained form natural sources like plant. Animals , minerals & they are used as such as they occur in nature without any processing except, drying & size reduction.
| Source | Example |
| Vegetable Source | Fennel, Dill, Clove and Senna |
| Animal Source | Honey, Bees wax, Shark liver Oil |
| Mineral Source | Talc, Chalk, Bentonite |
Work of Seydler.
Seydler was German scientist he wrote a book " Analecta Pharmacognistica " in 1815. In this book he used word pharmacognosy first time he coined (to Prepare) this word by combining two Greek words
1) Pharmakon: - Drug
2) Gignosco: - To acquire knowledge of
2) Work of Galen: - (131 - 200)
Galen was Greek pharmacist; he worked on extraction of chemical constituent from the plants. He developed various methods of extraction therefore the branch of pharmacy which deals with extraction of chemical constituent from plants & animals is called as galenical Pharmacy.
3) Hippocrates (460 - 360. B.C.)
Before the birth of Jesus. He was Greek scientist; he worked on human anatomy & Physiology Particularly on circulatory system & nervous system. He prepared famous oath for physicians, which is still taken by the physicians. He is known as father of medicine.
4) Indian History Of Pharmacognosy: -
It is about 5500 years old, in the suktas of Rigveda & Atharwaveda medicinal property of plant is given. There are several medicinal plants, which are given with there use. The old Ayurveda Books, Charak samhita & Sushrutsamtita described many medicinal plants.
5) Traditional Indian System of medicine (Indigenous) i. g. old system.
a) Ayurveda: - The old system of treatment in India. It is 5500 years old. Ayurveda believes there are 3 principles 1) cough. 2) Vat. 3) Pitta. Which are responsible to maintain health. If their equilibrium is disturbed persons suffers from diseases
Ayurveda cures the cause of disease. The principles of positive health and therapeutic measures embedded in this system relate to mental, physical, social and spiritual welfare of human beings. Drugs of Ayurveda are obtained mostly from plants.
Dosage of Ayurveda are 1) Bhasma (oxides of metals) 2) Quath (extracts) 3) Gutika (pills) 4) Lep (ointment) 5) Asava & Arishtha (Alcohol containing liquids.) 6) powder. 7) Medicated oils. There are eight braches of Ayurveda.
1. Kayachikitsa (Internal medicine)
2. Kumarbhritya (pediatrics)
3. Trachchikitsa (psychological medicine)
4. Shalakya Tantra [(CENT) Ears, Nose & throat]
5. Shalya Tantra (surgery)
6. Agada tantra (toxicology)
7. Rasayana tantra (geriatrics- medicines for the old persons)
8. Vajikaran tantra [Aphrodisiacs, drugs which are sexual stimulants.]
Sidha System of Medicine.
The "Siddhas" developed the Sidha system of medicine (Spiritual persons). It is old than ' Vedic culture ' it belongs to Dravidian culture. Like Ayurveda the medicines are prepared from plants. The literature of this system is given in Tamil Language. Like Ayurveda it believes that all objects in universe, are made from 5. Elements. 1) Earth. 2) Water. 3) Sky. 4) Air. & 5) Fire.
Diseases are identified by examination of pulse, voice, colour, of urine, tongue, and shadow. Etc. The books are written in Tamil.
Naturopathy & yoga: -
Naturopathy is not only a system of treatment but it also teaches the way of living. In naturopathy use of soil & water is important in treatment of diseases mudpacks & steam baths are used. Fasting is also used to treat diseases.
Yoga consists of two parts: -
1.Exercises (physical postures). 2. Meditation
1. Exercises: - Improves blood circulation in the body.
2. Meditation: - consists of 1) Breathing exercise 2) observance of austerity, 3) physical postures 4) Restraining of sense organ,, 5) Contemplation, 6).meditation & 7) samadhi.
This system helps us to improve physical, mental & social health. It improves personal behavior of the person.
DEFINATIONS
1) Carminative: -The Agent, which expels gases from G. I. tract, is known as carminative.
e. g. Fennel, Dill, Caraway
2) Expectorant: - The drug / agent which increases Fluidity of cough & helps in easy removal of cough are known as expectorant.
e. g. Vasaka, Tolu-balsam, Benzoin.
3) Purgative: - The drug which evacuate the bowl
e. g. Senna leaf, Castor oil, Rhubarb.
4) Laxative: - These are the purgatives, which have mild action.
e. g. senna
5) Cathartic: - These are drastic purgative stools produced are watery in nature.
e.g. Castor oil, Rhubarb.
6) Analgesic: - The drugs which relieves pain by acting on Central Nervous System. They are of two types
I) Narcotic Analgesics e. g. Opium
II) Antipyretic Analgesics e. g. Aconite
7) Antipyretic Analgesics: - The drug, which reduces, elevated body temp.
e. g. Cinchona bark
8) Diaphoretic: - Drug, which reduces, elevated body temperature by increasing rate of sweating.
e. g. Tulsi, Camphor Tulsi, Camphor
9) Diuretic: - The drug, which increases rate of Formation & excretion of urine, is known as diuretic.
e. g. Tea, Buchu leaves
10) Emetic: - The drug which produces vomiting.
e. g. Mustard, Ipecac Senega.
11) Febrifuge: - The drug which reduces the body temperature.
12) Hypnotic: - The drug which produces sleep, like Natural sleep, is known as Hypnotic e. g. Opium
13) Sedative: - The drug, which lowers activity of any organ or central Nervous System, is known as sedative. (Tranquillizer.)
14) Oxytocic: - The drug which causes contraction of uterus.
e. g. Ergot
15) Anthelmintic: - The drug, which kills or expels, worms from G. I. T.
e. g. Santonica flower, Chenopodium oil.
16) Appetizer: - The drug which increases desire for food
e. g. Cinchona, Nux-vomica.
17) Aphrodisiac: - An agent which stimulate sexual desire
e. g. lahsun.
18) Bitter: - Bitters are drugs having bitter taste, due to bitter taste they stimulate nerves and stimulate secretion of stomach and appetite.[S1]e.g. Cinchona, Nux vomica.
19) Counter irritant: - Counter irritant is a substance, which when applied is externally produces irritation. This irritation is mild in nature, this irritation reduce the original pain sensation.
e. g. Camphor, Turpentine oil, methyl salicylate.
20) Stomachic: - The drug, which increases secretion of gastric juice & function of stomach, digestion is known as stomachic e. g. Fennel, Dill, Gentian.
