Adulteration and Evaluation of Crude drugs

Recap In the last we have discussed about Methods of adulteration Commonly used substitutes in adulteration Evaluation for determining adulterants

Objectives On completion of this period, you would be able to know Organoleptic evaluation Microscopical evaluation Physical evaluation Chemical evaluation Biological evaluation Standards in pharmacopoeia

Evaluation of Crude Drugs Evaluation refers to the Standardisation of crude drugs It includes Identity of the crude drug and determination of its Quality and Purity Identity of the drug is confirmed by Comparing the sample with an authentic sample or Comparing with the Official Literature available

Evaluation of Crude Drugs Quality refers to the amount of Active chemical constituents present in the crude drug Purity refers to the freedom from admixture

Organoleptic (Morphological) Evaluation: It involves study of crude drugs by utilizing our organs of sense Gross morphology and other sensory characters like colour, size, shape, odour, taste, fracture, texture etc.,

Microscopical Evaluation Study of microscopical characters of the organised drug Types of cells, tissues present, cell contents like starch, calcium oxalate, mucilage, special structures like stomata or trichomes present or absent Microchemical tests useful in evaluating certain organised drugs

Microscopical Evaluation Quantitative microscopy Stomatal number Stomatal Index Vein-islet number Palisade Ratio

Physical Evaluation: Determination of typical physical constants Viscosity Swelling factor Melting point Specific gravity

Physical Evaluation: Refractive index Ash values Optical rotation Volatile oil content of crude drugs Moisture content

Foreign organic matter: Pharmacopoeia prescribe maximum limit for other parts of plants or other organic matter in many crude drugs and also include Animal excreta, Moulds or Insects

Extractive values The chemical constituents may be extracted with suitable solvent known as extractives Water soluble extractives : water soluble constituents Alcohol soluble extractives: Alkaloids, Glycosides, etc., Ether soluble extractives Volatile : Volatile oils Non-volatile : Resins

Volatile oil content Drugs containing volatile oil like Cinnamon, Clove etc., are evaluated by determining volatile oil content by Steam distillation

Ash values Refer to the amount of inorganic matter present in the crude drug or collected along with the drug Total Ash value Acid Insoluble Ash Water soluble Ash Sulphated Ash

Chemical Evaluation: It involves determination of Active chemical constituents Assays Total alkaloidal content Assayed by acid base titrations Non-aqueous titration.

Biological Evaluation: Some crude drugs cannot be evaluated satisfactorily by Chemical or physical methods They may be assayed by making use of Living tissue or organs Animals or Micro-organisms like Bacteria or fungi

Biological Evaluation Bacteria and fungus are used to determine Anti-bacterial and Anti-fungal activity For Biological assay of Vitamin – D containing substances guinea pigs are used. Bio-assay of digitalis is done on pigeons

Significance of Pharmacopoeial Standards Drugs should be uniform in quality Type of standards: Structural standards Analytical standards Physical constants

Pharmacopoeia The important pharmacopoeias are Pharmacopoeia is an official code Containing a list of established drugs The important pharmacopoeias are Indian Pharmacopoeia - I.P. British Pharmacopoeia - B.P. United States Pharmacopoeia- U.S.P.

Pharmacopoeial Standards The authenticity of a crude drug is established By references given in Pharmacopoeias.

Summary In this class we learnt about Organoleptic evaluation Microscopical evaluation Physical evaluation Chemical evaluation Biological evaluation Standards in pharmacopoeia

Quiz Confirmation of identity of crude drugs by studying microscopical characters comes under Morphological evaluation Physical evaluation Biological evaluation Microscopical evaluation

Frequently Asked Questions What is evaluation?. List out various evaluation methods. (April 2006) Define adulteration. Mention the various methods used in adulteration of drugs (April 2004)