III. Sources of Drugs.pptx

SOURCES OF DRUGS  SOURCES OF DRUGS 1) NATURAL A. Plants Oldest source of drugs used  empirically  leaves, seeds, flowers, roots, bark, etc. Problems: 1. Identification of plant 2. Climatic and social conditions of area 3. Season of...

SOURCES OF DRUGS  SOURCES OF DRUGS 1) NATURAL A. Plants Oldest source of drugs used  empirically  leaves, seeds, flowers, roots, bark, etc. Problems: 1. Identification of plant 2. Climatic and social conditions of area 3. Season of collection 4. Condition of storage 5. Standardization of active principle 6. Purity of active ingredient 7. Maintenance of supply line 8. Active principle is synthesized after detection  Leaves  The leaves of Digitalis Purpurea are the source Digitoxin and Digoxin, which are cardiac glycosides  Leaves of eucalyptus oil is an important component of cough syrup  Tobacco leaves give nicotine  Atropa belladonna gives atropine  Flowers  Poppy papaver somniferum gives morphine (Opoid)  Vinca rosea gives vincristine and vinblastine (anti-neoplastic drugs)  Rose gives rose water used as tonic  Fruits  Senna pod gives anthracine, which is purgative (used in constipation)  Calabar beans give physostigmine, which is cholinomimetic agent  Seeds  Seeds of Nux Vomica give strychnine, which is a CNS stimulant  Castor oil seed give castor oil  Roots  Ipecacuanha root gives Emetine used to induce vomiting as in accidental poisoning. It also has amoebicidal properties.  Rauwolfia serpentina gives reserpine, a hypotensive agent  Reserpine was used for hypertension treatment  Bark  Cinchona bark gives quinine and quinidine, which are antimalarial drugs. Quinidine has also antiarrhythmic properties.  Atropa belladonna gives atropine, which is anticholinergic  Hyoscyamus Niger gives Hyoscine, which is an anticholinergic  VARIOUS FORMS OF PLANT DRUG  Extract, infusions, decoction, powders, etc.  Chemicals (alkaloids, glycosides, oil, resins, tannins, gums etc.) isolated from different forms are used for humans and animals  B. Animals  Modern drugs  Active principles are proteins, oil and fats, enzymes and hormones  e.g. gonadotropins, heparin, insulin, thyroid extract and enzymes  Microorganisms  Antibiotics were derived from fungi and bacteria after the discovery of penicillin in 1928 and its use in 1940  Used for infective diseases  E.g. penicillin, streptomycin, tetracycline, chloramphenicol and erythromycin  C. Minerals  Metals, metalloids, non-metal substances and their compounds  E.g. iron, calcium, magnesium, aluminum, sodium, potassium, Sulphur, lithium, etc.  Minerals  Iron is used in the treatment of iron deficiency anemia  Mercurial salts are used for syphilis  Zinc is used as zinc supplement needed for body’s defensive (immune) system to properly work  Zinc oxide paste is used in wounds and eczema  Minerals  Iodine is antiseptic and maybe used as a supplement  Gold salts are used in the treatment of rheumatoid arthritis  Fluorine has antiseptic properties  Selenium as selenium sulphide is used in anti-dandruff shampoo  2.SEMI-SYNTHETIC  When the nucleus of drug obtained from natural source is retained but the chemical structure is altered  Complex molecules  Expensive and for impure natural compound  E.g. 6-aminopencillanic acid (fungus), semi-synthetic human insulin (pork insulin)  3. SYNTHETIC  Done in pharmaceutical laboratory  Organic or inorganic or combination of both compounds  E.g. chloroform, ether, nitrous oxide, chloral hydrate  Antipyretics, sulphonamides, antihistamines, anticonvulsants, anti anxiety etc RECOMBINANT DNA TECHNOLOGY  Process of “gene Cloning”  Involves cleavage of DNA by enzyme restriction endonucleases  The desired gene is coupled to rapidly replicating DNA (viral, bacterial or plasmid)  The new genetic combination is inserted into the bacterial cultures which allow production of genetic material RECOMBINANT DNA TECHNOLOGY  Human insulin, human proinsulin gene to form insulin  Growth hormone, tissue plasminogen activator, vaccines, interferon, erythropoietin, interleukins granulocyte-colony stimulating factor, RECOMBINANT DNA TECHNOLOGY  Advantages: Huge amounts of drugs can be produced Drug can be obtained in pure form Less antigenic  Disadvantages: Well equipped laboratory is needed Highly trained staff is required Complex and complicated technique