Physical standards are to be determined for drugs, wherever possible. These are rarely constant for crude drugs, but may help in evaluation, specifically with reference to Moisture content, Viscosity, Melting point, Solubility in different solvents, Optical rotation, Refractive index, Ash.Values and Extractives Volatile oil Content Foreign Organic Matter :

1. Evaluation of Crude drug
PRESENTED BY:
MR. PRITAM VIJAY JUVATKAR
ASSISTANT PROFESSOR
pvjuvatkar@rediffmail.com, +91 9987779536
KONKAN GYANPEETH RAHUL DHARKAR COLLEGE OF PHARMACY AND
RESEARCH INSTITUTE, KARJAT
UNIVERSITY OF MUMBAI

2. Evaluation of Crude
drug
 Evaluation of a drug means confirmation of
its identity and determination of its quality
and purity and detection of nature of
adulteration,
The evaluation of a crude drug is necessary
because of three main reasons
 Biochemical variation in the drug,
 Deterioration due to treatment and storage,
 Substitution and adulteration, as a result of
carelessness, ignorance or fraud.

3. Types of Evaluation of Crude drug
 Morphological or organoleptic evaluation
 Chemical evaluation
 Physical evaluation
 Microscopic evaluation
 Chromatographic techniques
 Spectrophotometric methods
 Biological evaluation
 Biotechnological method
3
Pritam Vijay Juvatkar 9987779536

4. Physical evaluation

5. Pritam Vijay Juvatkar 9987779536
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Physical evaluation
 Physical standards are to be determined for drugs, wherever possible.
 These are rarely constant for crude drugs, but may help in evaluation, specifically with
reference to
 Moisture content,
 Viscosity,
 Melting point,
 Solubility in different solvents,
 Optical rotation,
 Refractive index,
 Ash.Values and Extractives
 Volatile oil Content
 Foreign Organic Matter :

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Physical evaluation : Parameter 1
Moisture content :
 The percentage of active chemical constituents in crude drugs is mentioned on air-dried
basis. Hence, the moisture content of a drug should be determined and should also be
controlled.
 The moisture content is determined by heating a drug at 105°C in an oven to a constant
weight For the drug containing volatile active constituents, the toluene distillation method is
followed.
 Drugs Moisture Content (%) w/w
 Aloes not more than 10 %
 Digitalis not more than 05 %
 Acacia not more than 15 %

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Physical evaluation : Parameter 2 & 3
Viscosity:
 Viscosity of a liquid is constant at a given temperature and is an index of its, composition.
Hence it can be used as a means of standardising liquid drugs
 Liquid paraffin 64 centistokes at 37.8 °C (Not Less Than
Melting point:
 In case of pure chemicals or phytochemicals, melting points are very sharp and constant.
 Since the crude drugs from animal or plant origin contain the mixed chemicals, they are
described with certain range melting point.
 Beeswax 62 - 65.
 Wool fat 34 - 44

8. Pritam Vijay Juvatkar 9987779536
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Physical evaluation : Parameter 4 & 5
Solubility:
 The presence of adulterant in a drug could be indicated by solubility studies
 Castor oil is soluble only in 3 volumes of 90 per cent alcohol, while the
adulterated form may show good solubility in alcohol.Liquid paraffin 64
centistokes at 37.8 °C (Not Less Than
 Alkaloid bases are soluble in chloroform, while alkaloidal salts are soluble in
polar solvent.
Optical rotation:
 Certain substances are found to have the property of rotating the plane of polarised light in the
pure state or in the solution.
 Thus, they are described to be optically active and this property is known as optical rotation
 Normally, the optical rotation is determined at 25°C using sodium lamp as the source of light.
 Caraway oil + 75° to + 80°
 Castor oil 3.5° to + 6.0°

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Physical evaluation : Parameter 6
Refractive index:
 When a ray of light passes from one medium to another of different density, it is bent from
original path.
 Thus, the ratio of the velocity of light in vacuum to its velocity in the substance is termed
as refractive index of the second medium.
 Depending upon purity, it is constant for a liquid and can be considered as one of the
criteria for its standardization,
 Castor oil 1.4758 . to 1.527
 Clove oil 1.527 to. 1.535

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Physical evaluation : Parameter 7
Ash Values :
 The residue remaining after incineration is the ash content of the drug, which simply represents inorganic
salts, naturally occurring in drug or adhering to it or deliberately added to it, as a form of adulteration.
 Physiological ash: Total ash of the drug is inclusive of 'Physiological ash' as well as non-physiological ash.
 Physiological ash is derived from the plant tissues, while non-physiological ash consists of residue of the
extraneous matter (such as sand, soil, etc.) adhering to the herb itself.
 Total ash usually consists of carbonates, oxides, phosphates, silicates and silica.
 Acid-insoluble ash, which is a part total ash insoluble in dilute hydrochloric acid, is a recommended for
certain drugs. Adhering dirt and sand may be determined by acid-insoluble ash
Drug Total Ash (%w/w) Acid insoluble ash (%w/w)
 Cardamom 06.0 3.50
 Clove 07.0 0.75

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Physical evaluation : Parameter 8
Extractives:
 The extracts obtained by exhausting crude drugs are indicative of approximate measures of their chemical
constituents.
 Taking into consideration the diversity in chemical nature and properties of contents of drugs, various solvents
are used for determination of extractives.
 The solvent used for extraction is in a position to dissolve appreciable quantities of substances desired.
Water-soluble extractives:
 This method is applied to drugs which contain
water-soluble active constituents of crude drugs,
such as tannins, sugars, plant acids, mucilage,
glycosides, etc.
Drugs Water-soluble extractive (%w/w)
Aloe not Iess than 25.0
Glycyrrhiza not less than 20.0
Alcohol-soluble extractives:
 Alcohol is an ideal solvent for extraction of various
chemicals like tannins, resins, etc.
 Therefore, this method is frequently employed to
determine the approximate resin content of drug.
 It is also used as an official method for assay in case
of myrrh and asafoetida.
Drugs Alcohol-soluble extractive (%w/w)
Aloe not less than 10.0
Benzoin not less than 90.0 (Siam benzoin)
75.0 (Sumatra benzoin)

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Physical evaluation : Parameter 9
Volatile oil Content :
 Pharmaceutical significance of aromatic drugs is due to their odorous principles i.e. volatile oiIs.
 Such crude drugs are standardized on the basis of their volatile oil content
Drugs Volatile oil Content (%w/w)
Caraway not less than 2.5
Fresh lemon peel not less than 2.5
Foreign Organic Matter :
 The parts of the organ or organs other than those named in the definition and description of the drug are
defined as foreign organic matter.
 The maximum limit for the foreign organic matter is defined in the monograph of crude-drugs.

13. Thank You
PRESENTED BY:
MR. PRITAM VIJAY JUVATKAR
ASSISTANT PROFESSOR
pvjuvatkar@rediffmail.com, +91 9987779536
KONKAN GYANPEETH RAHUL DHARKAR COLLEGE OF PHARMACY AND
RESEARCH INSTITUTE, KARJAT
UNIVERSITY OF MUMBAI

14. Disclosure
This Presentation is meant for Study Notes for B.Pharm Students only. Please
do not take as a reference for treatment for an ailments or other usage
PRESENTED BY:
MR. PRITAM VIJAY JUVATKAR
ASSISTANT PROFESSOR
pvjuvatkar@rediffmail.com, +91 9987779536
KONKAN GYANPEETH RAHUL DHARKAR COLLEGE OF PHARMACY AND RESEARCH INSTITUTE, KARJAT
UNIVERSITY OF MUMBAI