1. Pharmacognosy Definition
Pharmacognosy is an applied science which treats medicinal and related products of crude or primary type obtained from :
plants
animals,
minerals
marine sources.

2. In short, Pharmacognosy is a study of crude drugs of natural sources including:
knowledge of the history
distribution,
cultivation,
collection,
processing, for market and preservation,
study of physical, chemical and structural characters
uses of crude drugs.

3. Pharmacognosy
The word Pharmacognosy is derived from the Greek "Pharmakon", meaning a drug or poison and "gnosis" meaning to acquire a knowledge of and literally meaning "the entire knowledge of drug".

4. Pharmacognosy
Pharmacognosy also includes the study of other materials used in Pharmacy such as
Suspending (drug is suspended in a solution)
Disintegrating (Breaking the compound)
Flavoring agent
Antibiotics
Hallucinogenic (Psychoactive drugs which changes in emotion and consciousness)
Poisonous

5. Scope of Pharmacognosy
Pharmacognosy has an important role in the development of different sciences:
The pharmacognosist should have the knowledge of terms covered under botany and Zoology
The knowledge of plant taxonomy, plant breeding and plant genetics is helpful in the development of cultivation technology for medicinal plants
Plant chemistry (Phytochemistry) is concerned with the variety of substances that are synthesized and accumulated by plant and deals with the structural elucidation of these substances.

6. Scope of Pharmacognosy
The technology involving for extraction, purification and characterization of pharmaceuticals from natural sources helps in the advancements of natural and physical sciences.
The knowledge of chemtaxonomy, biogenetic pathways for the formation of medicinally active primary and secondary metabolites is important for complete understanding of the subject ‘Pharmacognosy’

7. Scope of Pharmacognosy
Pharmacognosy is an important link between Pharmacology and Medicinal chemistry. As a result of rapid development of plant chemistry and pharmacological testing methods, new plant drugs are now used as purified phytochemicals. The knowledge of pharmacology is essential for understanding the action of drug on animals and human systems.
Pharmacognosy is a vital link between Ayurvedic and allopathic systems of medicines.

8. Crude Drugs
It means the harvested and usually dried plant or animal sources of pharmaceutically or medicinally useful products before they have undergone extensive processing or modification.
Crude drugs are derived from the mineral, vegetable and animal kingdoms.
Crude drugs of vegetable, animal and mineral origin form the subject matter with which pharmacognosy is concerned.

9. Examples of Crude Drugs
Entire plants or animals: Mentha, Lobelia, Cantharidis, Cochineal.
Entire organs of plants or animals: Senna, Clove, Fennel, Linseed, Quassia, Cinchona, Liquorice, Thyroid gland.
Minerals: chalk, kaolin, talc.
Substances derived from plants or animals (unorganized): opium, aloes, tragacanth, resins, musk, beeswax, gelatin.

10. Description of each individual drug
Origin: including biological and geographical sources, a knowledge of the history and name of the drug.
Cultivation and preparation: including details of cultivation of the medicinal plants, methods of collection, drying, packing and other treatment of the drug during its preparation for the market.

11. 3. Characters: including the physical characters such as dimensions, surface characters, fracture and the sensory characters such as colour, odour and taste. The histological characters which help in the identification of the drug in powdered form, are of fundamental importance.
4. Constituents and tests: constituents include both the reputed active constituents and also other constituents and reserve food materials. Chemical identity tests are based on the nature of constituents

12. 6 Evaluation of the physical and chemical characters of the drug.
5. Adulterants: including materials added fraudulently and matter which has become associated with the drug owing to carelessness in handling during collection, preparation, packing and transport.
6 Evaluation of the physical and chemical characters of the drug.
7. Uses and application of the drug in medicine.

13. History of Pharmacognosy
Ancient Egyptian period
The ancient Egyptians 3000 B.C. were experts in using drugs for curing diseases.
The healing of the sick was undertaken by priest doctor and pharmacist "Son" who prescribed and prepared medicines.
Crude drugs of vegetable origin used included Aloes, Gum, Myrrh, Poppy, Pomegranate, Colocynth, Linseed, Squill, Coriander, Onion, Anise, Melon, Castor, etc...

14. The first recorded prescriptions were found in Egyptian tombs
The first recorded prescriptions were found in Egyptian tombs. These were the Hieratic papyri (by Edwin Smith in 1862), Ebers papyrus (by Edwin Smith in 1862, Hieratic language), the Gynecologic papyrus.

15. The Babylonians
The Babylonian medicine was known (Laws of Hamorabi 772 B.C.).
the drugs used were mainly of vegetable origin.
The drugs used include 250 materials of plant, and 180 materials of animal source. Many of these drugs were known to the ancient Egyptians.

16. Old Indian medicine
The "Riveda" and Ayurveda (Acoko 2000 B.C.), contained the sacred medicinal plants.
The collection of plant materials was done only by an innocent, pure, religious person.
The fresh plants were considered to be the most effective.
The most celebrated Indian drugs were; Sandal wood, Clove, Pepper, Cardamom, Caraway, Ginger, Benzoin, Cannabis, Castor oil, Sesame oil, Aloes, etc...

17. The old Chinese medicine
Beside the famous acupuncture, the Chinese medicine is very acknowledged for the herbal medicine.
The Pen Ts'ao Kang Moa 1000 B.C. contained an incredible number of medicinal plants and drugs of animal origin.
Their book includes many recipes for every disease. Among the plants and minerals highly esteemed for its magic health including power were; Ginseng, Rhubarb, Ephedra, Star Anise, Pomegranate, Aconite.... Opium is a very old Chinese drug for diarrhea and dysentery.

18. The Greek and Romans
Pythagoras (560 B.C.) used drugs as Mustard and Squill, etc....
Hippocrates (466 B.C.) was familiar with numerous drugs, and wrote "Corpus Hipocraticum 460 B.C.".
The Greek Empire was followed by that of the Romans Dioscorides who was a Greek by birth he was the first to describe drugs and his work "Greek Herbal of Dioscorides" included 5000 medicinal plants in addition to animal and mineral drugs.

19. Islamic Contribution
In Islamic writings were found the first beginnings of chemistry, the name of which is derived from an Arabic word "Kemia"; as were also such familiar words alcohol and alkali.
The Arabs added numerous new plants and medicaments to those already known to the Greeks and Romans.
In their days, pharmacy attained its highest reputation and became an independent branch of medicine.
It is interesting to note that the first dispensary was opened in Baghdad, the center of trade in those days.

20. Official and unofficial drugs
Drugs are either official or unofficial. An official drug is one which is listed and described in a book recognized by the government as the legal authority for standards "Pharmacopoeia"

21. Origin of drugs
There are two origins for each drug; the natural or biological, as well as, the geographical origin.
The commercial origin is also of interest in case of certain drugs.

22. The natural or biological origin (source(
The natural origin of a drug is the plant or animal yielding it, if a plant, botanical origin or botanical source and if an animal, zoological origin or source.

23. Geographical sources of drugs
The geographical source or Habitat is the region in which the plant or animal yielding the drug grows.
Plants growing in their native countries are said to be indigenous to these regions, e.g. Aconitum napellus of the mountainous regions of Europe, Hyoscyamus muticus of Egypt, Cannabis sativa of India.
Plants are said to be naturalized when they grow in a foreign land or in locality other than their native home.

24. CLASSIFICATION OF CRUDE DRUGS

25. Classification of crude drugs
The term crude drugs implies to the products from plant and animal origins and mineral kingdom found in the raw form.
The term refers to the natural product that has not been advanced in value or improved in condition by any process or treatment beyond that what is essential for its proper packing and prevention from deterioration.

26. Crude drugs are broadly divided into the following two main groups on the basis of their apparent morphological forms of cellular and structural organisation-
Organised crude drugs are composed of definite organised histological or cellular structures and tissues.
Unorganised crude drugs are devoid of any definite histological or cellular structures and are derived from plants and animals by different extraction processes or as natural secretions.

27. The Organised crude plant drugs are again further divided into lie following two groups –
a) Drugs from Overground organs, which include all drugs that ire derived from the overground or aerial parts or organs of plants.
(b) Drugs from Underground organs, which include all drugs that are derived from underground or subterranean parts or organs of plants.

29. The systems of classification of crude drugs may be aimed accordingly as follows a. Alphabetical system b. Taxonomical system c. Morphological system d. Pharmacological or therapeutic system e. Chemical system f. Chemotaxonomic classification

30. Alphabetical classification:
In this system crude drugs are arranged in alphabetical order using their English or Latin names.
The Pharmacopoeias and other official publications use this system is the simplest method of arranging crude drugs and is particularly suitable for classifying drugs having no connecting features of a scientific nature.
Some of the pharmacopoeias and books which are classify crude drugs according to this system are:
British pharmacopoeia 1980
United states pharmacopoeia Formulary 1980.

31. Taxonomical classification:
In this system crude drugs are arranged according to the natural groups (e.g. families) of their sources. Thus all the drugs obtained from plants of the family Umbelliferae are grouped together as umbelliferous drugs, those from Solanaceae are grouped together as Solanaceous drugs and so on.

32. The taxonomical classification of some drugs derived from dicotyledonous plants is as follows:
Phylum : Spermatophyta
Division: Angiospermae
Class : Dicotyledons
Order: Rosales
Family: Leguminosae (Fabaceae)
Sub-family: Papilionaceae
Genus: Glycyrrhiza
Species: Glycyrrhiza glabra

33. Morphological classification:
In this system the organised drugs are arranged according to the morphological similarities and dissimilarities of various plant parts which constitute the drugs.
Thus all drugs, irrespective of their chemical constituents and source are grouped together.
Organized drugs are divided into parts of plants like leaves, flowers, fruits, seeds, barks, roots etc.
Unorganised drugs are grouped in this system as latices, extracts, gums, resins, oils, fats and waxes,

34. Examples of Morphological classification
Seed Nux vomica
Leaves Senna
Barks Cinchona
Dried latex Opium
Gum Acacia

35. Pharmacological or therapeutic classification:
This system is based on the pharmacological actions and therapeutic properties of the crude drugs.
In this system, all the cathartic drugs are brought together regardless of their morphology, taxonomy or chemical relationship. Thus, Podophyllum (a rhizome), Jalap (a tuberous root), Cascara (a bark) and Castor oil (oil) are considered at the same time when this system is used.

36. Crude drugs are grouped according to the pharmacological action or therapeutic uses of their main active constituents
Drugs acting on gastrointestinal tract
Carminatives Menta
Emetics Ipecacuanha
Bulk laxtives Agar
Purgatives, Constipation Senna
Peptic ulcer treatment Liquorice
B. Drugs acting on respiratory system
Expectorants Liquorice
Antitussive Opium (codeine)
Bronchodilators Ephedra

37. C. Drugs acting on cardio-vascular system
Cardiotonic Digitalis
Cardiac depressants Chichona
Antihypertensive Rauwolfia
D. Drugs acting on autonomic nervous system
Adrenergics Ephedra
Cholinergics Physostigma
Anticholinergics Belladona
E. Drugs acting on central nervous system
Central analgesics Opium
CNS stimulants Coffee

38. F. Drugs acting on antispasmodics system
Smooth muscle relaxants Opium
Skeletal muscle relaxants Curare
G. Anticancer Vinca
H. Antirheumatics Aconite
Anthelmentics Male fern
J. Astringent Black catechu
K. Antimalaria Cinchona

39. Chemical classification:
The crude drugs are divided into groups according to their principal chemical constituents. Thus all alkaloid-containing drugs are put into one group regardless of other consideration.
Similarly all crude drugs containing glycosides are grouped together and so on. Since the pharmacological actions and therapeutic uses of drugs depend on their chemical constituents, this system of classification appears to be an ideal one.
Moreover, certain plant families exhibit definite types of chemical principles, e.g., tropane alkaloids characterize the Solanaceae family; volatile oils are common in the Umhelliferae family, while Pinaceae contains mainly oleoresins.

40. Chemotaxonomic classification
It has been revealed that there is a close relationship between chemical constituents of plants and their taxonomical status. Certain chemical constituents are found to characterize certain botanical groupings