SOURCES OF DRUGS

Sources of drugs:

Sources of drugs Dr Badar Uddin Umar

Learning Objectives:

Learning Objectives Different drug sources Constituents of different drug sources Example of each Chemical and physical properties of each Uses

Natural Sources:

Natural Sources Vegetable source Animal source Mineral source Microbiological source

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Synthetic source: Inorganic source Organic source Combination of these two Semi synthetic source: By altering structures of naturally occurring drugs

Vegetable or Plant Source:

Vegetable or Plant Source Oldest of all Various parts of plants like-leaves, flowers, seeds, roots, stems & bark etc. are used e.g. – Belladonna leaves, Belladonna roots, Cinchona bark, Digitalis leaves, Nux vomica seeds, seed head of unripe opium poppy etc.

Active principles of plant source:

Active principles of plant source Alkaloids Glycosides Fixed oils Volatile oils Saponins Gums Mucilages Carbohydrates Resins

Alkaloids:

Alkaloids Alkaloid = alkali + oid ( alkali like substances ) Very active, basic, cyclical nitrogenous compounds found in plants White, crystalline in nature Intensely bitter in taste Insoluble in water but soluble in ether, alcohol etc. Produce salt with acid Their salts are soluble in water Their names end with “ine” e.g.- Atropine, Morphine, Quinine, Nicotine, Strychnine, Reserpine, Pilocarpine etc. More than one alkaloid may be present in same source

Alkaloids (Examples):

Alkaloids (Examples) Belladonna: Atropine Hyoscine Hyosciamine Cinchona: Quinine Quinidine Cinchonine Cinchonidine Cocaine: Cocaine Cegonine Ergot: Ergotamine Ergometrine Ergine Opium: Morphine Codeine Papaverine Noscapine

Glycosides:

Glycosides Condensation products of sugars with various organic hydroxyl compounds Very active Complex structures containing- C, H and O Ether like substances Hydrolyzed by acids or certain enzymes in the presence of water in to a sugar and a non sugar part Non sugar part (aglycone or genin) is active part

Glycosides (Contd.):

Aglycone part modifies penetration, reactivity and persistence of action of glycosides Their names end with “in” e.g. digoxin, digitoxin, gitoxin, gitalin, ouabin, stopanthin etc. They can be- Glucoside, Galactoside or Fructoside according to sugar part. Glycosides (Contd.)

Oils:

Oils Two types:- Fixed oils and Volatile oils Fixed oils are mixtures of glycerol esters of high mol. wt. aliphatic acids (fatty acids) like- oleic acid, palmitic acid, stearic acid Bland, non irritating,

Fixed oils:

Fixed oils Leaves greasy mark on paper Insoluble in water, lighter than water but soluble in ether, alcohol etc. Can’t be dissipated by heat Can’t be distilled without being decomposed Forms soaps with alkali e.g. Olive oil, Castor oil, Chaulmoogra oil

Volatile oils:

Volatile oils Odorous principles hence called essential oils Obtained by distillation of various parts of plants Evaporated when exposed to air in room temp. Colorless when fresh but turns dark on standing due to oxidation and resinification So they must be stored in amber colored glass bottle in a cool and dry place

Volatile oils:

Slightly soluble in water giving their taste and odor to water Examples:- Liquid hydrocarbons (momotrepens):- Peppermint oil, Spearmint oil, Wintergreen oil, Lemon oil, Clove oil Crystalline Stearoptenes:- Menthol, Thymol, Eugenol, Camphor etc. They are used as local analgesics, soothing agents, antiseptics, diuretics and counter irritants etc. Volatile oils

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SAPONINS - Senega GUMS - Gum acacia, Agar, Psyllium seeds MUCILAGES - Tragacanth CARBOHYDRATES - Dextrose, Sucrose, Fructose, Alcohols RESINS - Colophony

Animal sources:

Animal sources Past days: Dried toad skin - for treatment of tooth ache, gum bleeding (China) Cod fish - Cod liver oil source of Vit. A & D Present days: Insulin from pork (porcine), Cow & buffalo (bovine) IgG is prepared by injecting specific antigens to different animals which is later used as vaccines (antiserum) hMG (human menopausal gonadotropin) from post menopausal women urine contain mixture of FSH & LH hCG (human chorionic gonadotropin) produced by placenta, obtained from pregnant woman’s urine

Mineral Source:

Mineral Source Metalloids, Metals and Non metals and their compounds are used. e.g. Iron, Iodine, Calcium, Gold - in deficiency states Magnesium trisillicate, Aluminium hydroxide as antacids Barium – in radiology as diagnostic tool Mercury – as diuretic (also used for syphilis in the past)

Microbiological Source:

Microbiological Source Many antibiotics are isolated from different fungi etc. Example- Penicillin from Penicillum notatum Erythromycin from Streptomyces erythreus Streptomycin from Streptomyces griseus Cephalosporins from Cephalosporium acremonium Tetracycline from Streptomyces aureofaciens

SYNTHETIC SOURCE:

SYNTHETIC SOURCE Organic Inorganic Combination of these two Latest of all Drugs are produced in laboratory or in pharmaceutical industry Drugs are more potent and effective Free of many impurities

SEMISYNTHETIC SOURCE:

SEMISYNTHETIC SOURCE Some of the drugs are altered structurally in the laboratory to get newer agents with less adverse effects, prolonged duration of action and better pharmacological actions Ampicillin, Amoxycillin are semisynthetic Penicillins. Heroin is obtained from Morphine

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