Post on 23-Dec-2015
CRUDE DRUGS AND THEIR CLASSIFICATION
SOURCES OF CRUDE DRUGS
They may be obtained from
vegetable, animal and mineral
sources.
They form the subject matter of
Pharmacognosy.
Pharmacognosy is concerned mainly
with naturally occurring substances
of medicinal importance.
It is, however, not entirely limited to
such substances.
Others may include substances such
as;
Surgical dressings prepared from
natural fibres
Flavouring and suspending agents
Disintegrants
The term crude drug refers generally to
products of plant and animal origin found
usually in their raw state/form
The term may also apply to
pharmaceutical products obtained from
the mineral kingdom.
DEFINITION OF CRUDE DRUG
Crude drugs may be defined as any natural
product that has not been advanced in
value or improved in condition by any
process or treatment beyond that which is
essential for its proper packing and
prevention from deterioration.
SOURCES OF CRUDE DRUGS
The most important natural sources of
drugs are;
Higher plants
Microbes
Animals
Marine organisms
TYPES OF CRUDE DRUGS
2 types exist depending on this type of
classification;
1. Organized drugs
2. Unorganized drugs
ORGANIZED DRUGS
These are drugs obtained from the direct
parts of the plants and containing cellular
tissues
E.g. Rhizomes, barks, leaves, fruits, entire
plants, hairs and fibres
EXAMPLES OF ORGANIZED DRUGS
Leaves– Digitalis, Eucalyptus, Mint, Senna,
Spearmint, Squill, Tulsi, Vasaka, Coca, Buchu,
Hyoscyamus, Belladonna, Tea.
Barks–Cascara, Cassia, Cinchona, Cinnamon,
Quillia.
Flowering parts– Clove, Pyrethrum,
Chamomile.
Fruits– Anise, Bitter Orange peel, Capsicum,
Caraway, Cardamom, Coriander, Dill, Fennel,
Lemon peel, Star anise.
Seeds– Bitter almond, Black Mustard,
Cardamom, Colchicum, Ispaghula,, Linseed,
Nutmeg, Nux vomica.
Roots and Rhizomes– Colchicum corm,
Dioscorea, Garlic, Ginger, Ginseng,
Glycyrrhiza.
UNORGANIZED DRUGS
These are drugs which are prepared from
plants by some intermediate physical process
such as incision, drying or extraction and not
containing any cellular plant tissue
E.g. Aloe, honey, beeswax, essential oil
DIFFERENCES BETWEEN ORGANIZED AND UNORGANIZED DRUGS
Organized Drugs Unorganized Drugs
These may be of plant or animal origin.
These may be of plant, animal or mineral origin.
These are direct part of plants or animals.
These are the product of plant or animals.
These have well defined cellular structure.
These do not have well defined cellular structure.
Generally identified by morphological character.
Generally identified by organoleptic properties.
IMPORTANCE OF CRUDE DRUGS
Plant-derived medicines are useful
therapeutic options and often provide a safe
form of therapy.
Provide lead compounds for the development
of new drugs.
CLASSIFICATION
Classification of crude drugs may include;
Alphabetical classification
Morphological classification
Pharmacological classification
Chemical classification
Taxonomic classification
Pharmacological classification
CHARACTERISTICS OF AN IDEAL SYSTEM OF CLASSIFICATION
An ideal method of classification of crude
drugs should be;
Simple
Easy to use
Free from confusion and ambiguities
1. ALPHABETICAL CLASSIFICATION
Alphabetical classification is the simplest
way of classification
Crude drugs are arranged in alphabetical
order of their:
Botanical names
Common names
Local/ vernacular names
The following pharmacopoeia classify
crude drugs according to this system:
British Pharmacopoeia
British Herbal Pharmacopoeia
Ghana Herbal Pharmacopoeia
United States Pharmacopoeia and National
Formulary
European Pharmacopoeia
ADVANTAGES OF ALPHABETICAL SYSTEM OF CLASSIFICATION
It is easy and quick to use
There is no repetition of entries and is
devoid of confusion.
In this system location, tracing and addition
of drug entries is easy
DISADVANTAGE
There is no relationship between previous
and successive drug entries
E.g. Acacia, Benzoin, Cinchona, Dill, Ergot,
Fennel, Gentian, Hyoscyamus, Ipecacuanha,
Jalap, Kurchi, Liquorice, Mints, Nuxvomica,
Opium, Podophyllum, Quassia, Rauwolfia,
Senna, Vasaka, Wool fat, Yellow bees wax,
Zeodary.
2. MORPHOLOGICAL CLASSIFICATION
In this system, the drugs are arranged
according to the morphological or external
characters of the plant parts or animal parts.
i.e. which part of the plant is used as a drug
e. g. leaves, roots, stem
3. PHARMACOLOGICAL CLASSIFICATION
This involves grouping of drug according
to their pharmacological action.
This is also referred to as therapeutic
classification of drugs.
Drugs like digitalis, squill and
strophanthus having cardiotonic action
are grouped together irrespective of their
parts used or their phytoconstituents.
CLASSIFICATION OF DRUGS BASED ON PHARMACOLOGICAL ACTION
Pharmacological Action Drugs
Anticancer Vinca, Podophyllum, Taxus
Anti-inflammatory Colchicum, Turmeric
Antiamoebic Ipecac root, Kurchi bark
Antiasthmatic Ephedra, Lobelia
Anthelminthic Male fern, Quassia wood
Antispasmodic Datura, Hyoscyamus
Astringent Catechu
Analgesic Opium, poppy
Bitter tonic Quassia wood, Nux-vomica, Gentian
Carminatives Coriander, fennel, clove, peppermint
Purgatives Senna, Rhubarb
Expectorant Tulsi, Balsam of Tolu
Cardiotonic Digitalis, Squill, Strophanthus
Tranquilizers Rauwolfia Roots
ADVANTAGE
This system of classification can be used for
suggesting substitutes of drugs if they are not
available at a particular place or point of time.
DISADVANTAGE
Drugs having different action on the body gets
classified separately in more than one group that
causes ambiguity and confusion.
E.g. Cinchona is an antimalarial drug because of
presence of quinine but can be put under the group
of drug affecting heart because of antiarrythymic
action of quinidine.
CHEMICAL CLASSIFICATION
The crude drugs are divided into different
groups according to the chemical nature
of their relevant constituent.
The chemical classification of drugs is
dependent upon the grouping of drugs
with identical constituents.
CHEMICAL CLASSIFICATION
1. Carbohydrates
Gums - Acacia, Tragacanth, Guargum
Mucilages - Plantago seed
Others include Starch, Honey, Agar, Pectin,
Cotton
2. GLYCOSIDES
Anthraquinone Glycosides - Aloe, Cascara,
Rhubarb, Senna
Saponins Glycosides - Quillaia, Arjuna,
Glycyrrhiza
Cyanogenetic Glycosides - Cassava
Isothiocyanate Glycosides - Mustard
Cardiac Glycosides - Digitalis, Strophantus
3. TANNINS
Tannins are astringent, bitter plant based
polyphenols that either bind or precipitate
proteins.
The astringency from tannins causes a dry
and puckery feeling in the mouth.
E.g.- Guava, Tea
4. VOLATILE OILS
Monoterpenes and sesquiterpenes
obtained from plants.
Examples- Cinnamon, Fennel, Dill,
Caraway, Coriander, Cardamom,
Orange peel, Mint, Clove
5. LIPIDS
Fixed oils – Castor, Olive, Almond, Shark
liver oil
Fats – Theobroma, Lanolin
Waxes – Beeswax, Spermaceti
6. ALKALOIDS
Nitrogenous substances of plant origin
Pyridine and Piperidine – Lobelia,
Nicotiana
Tropane - Coca, Belladonna, Datura,
Stramonium, Hyoscyamus, Henbane
Quinoline – Cinchona
Isoquinoline – Opium, Ipecac, Calumba
Indole – Ergot, Rauwolfia
Amines – Ephedra
Purine bases – Tea, coffee
TAXONOMIC CLASSIFICATION
Based on an accepted system of system of botanical classification
Grouped into:KingdomPhylum OrderFamilyGenusSpecies
ADVANTAGES
Allows for precise and ordered arrangement of drugs.
Accommodates any drug without ambiguity
MAJOR PLANT DRUGS CURRENTLY USED IN MEDICINE
DRUG PLANT SOURCE USE(S)
Vinblastine Catharanthus roseus
Anticancer
Vinblastine Catharanthus roseus
Anticancer
Reserpine Rauvolfia serpentina
Antipsychoyic, antihypertensive
Quinine Cinchona sp. Antimalarial,amoebic dysentery
Pilocarpine Pilocarpus jaborandi
Antiglucoma
Cocaine Erythroxylum coca
Topical anesthetic
DRUG PLANT SOURCE USE(S)
Codeine Papaver somniferum
Antitussive
Atropine Atropa belladonna
Spasmolytic
Artemisinin Artemesia annua
Antimalarial
Taxol Taxus baccata, T. brevifolia
Breast and ovarian cancer
Allicin Allium sativum Antifungal, amoebiasis
Morphine Papaver somniferum
Narcotic analgesic
MEDICAL TERMINOLOGIES
Arthritis -Inflammation of a joint
Ascites -Abnormal accumulation of fluid in
the peritoneal cavity
Asphyxia -Inability to breath
Atrophy -Wasting of a tissue or organ
Carcinogenic- Causing cancer
MEDICAL TERMINOLOGIES
Carcinoma- A malignant epithelial tumour
eventually becoming fatal
Cardiotonic- An agent that has a
stimulating effect on the heart; increasing
the strength and tone of the heart.
Cardiac depressant- Slowing the action of
the heart
Carminative Drug- causing the release of
stomach or intestinal gas
MEDICAL TERMINOLOGIES
Cathartic -Having the power of cleaning the
bowels-purgative
Decongestant - Relieving congestion, as of
the mucous membrane
Demulcent – Soothing action on inflammed
mucous membranes
Dermatitis - Irritation or inflammation of the
skin
MEDICAL TERMINOLOGIES
Diuretic - Promoting the flow of urine
Dysmenorrhoea - Difficult or painful
menstruation
Dyspepsia – Difficulty in digestion
Dysuria - Difficulty or pain while passing urine
Emetic -Causing vomiting
MEDICAL TERMINOLOGIES
Expectorant - Aiding the secretion of the mucous
membrane of the air passages and the removal of
fluid
Febrifuge - Anything which reduces fever
Haematemesis - Vomiting of blood
Haematuria - The presence of blood in the urine
Heamatinic: Therapeutic agent that causes
increase in the heamoglobin content of the blood.
MEDICAL TERMINOLOGIES
Insomnia: Difficulty in sleeping or staying
asleep.
Mydriatic: Drug that causes dilatation of the
pupil.
Sternutatory: a substance that causes
sneezing
Vermifuge: a remedy that causes expulsion
of worms or parasites.
Xerostomia: Anbormal dryness of the mouth