PHARMACOLOGY

 COMPOSITION OF DRUGS ::

Drugs obtained from any source may be inorganic or organic in nature Inorganic drugs have simple formula whereas organic drugs have a complex one :

(A) Inorganic Drugs : 1. Acids 2. Bases 3. Salts 

(B) Organic Drugs :: 1.Alkaloids 2.Glycosides 3.Oils 4.Tannins 5.Gums 6.Resins 7.Antibiotics 8.Hormones 

    In pharmacy curriculum drug composition and properties etc are taught under pharmaceutical chemistry and pharmacognosy subjects However alkaloids and glycosides being the most important are mentioned briefly hereafter 

Alkaloids :: 

These are naturally occurring complex basic nitrogenous compounds having physiological pharamacological and therapeutic importance They are of plant origin but some of them are of animal origin and the rest are synthetically prepared 

Chemically they are nitrogenous bases with characteristics similar to substituted ammonia Their Formula have C.H.O and N. while a few alkaloids contain S and P also 

    They are non volatile colourless crystalline solids insoluble in water but their salts are water soluble They dissolve in many of the organic solvents like ether ethanol and chloroform 

    Alkaloids are widely distributed in the plant kingdom embeded in various parts of plants and trees Quinine in cinchona bark emetine in ipecacuanha roots and morphine alkaloids in the dried juice of unripe poppy capsules are common examples few are obtained from fungi for examples muscarine from poisonous mushrooms and ergot alkaloids like ergotoxin from calviceps purpurea or rye grains 

            Alkaloids may be classified chemicaly as follows ::

1.Quinoline (quinine quinidine )

2.Pyridine (lobeline ) 

3.Pyridine pyroline (atropine nicotine ) 

4.Isoquinoline (papaverine emetine ) 

5.Phenanthrene (morphine codeine thebaine )

6.Indole (reserpine eserine) 

7.Imidazole (pilocarpine)