This document discusses methods for evaluating crude drugs and herbal formulations. It outlines various compendial parameters for evaluation including identification, foreign matter, loss on drying, moisture content, residue on ignition, water and alcohol soluble extractives, heavy metals, pesticide residues, microbial contamination, aflatoxins, and assays. Methods are described for many of these tests including identification by macroscopic and microscopic examination, TLC/HPTLC. Loss on drying is determined by drying a sample to a constant weight. Total ash involves incinerating a sample and calculating the percentage of residue. Water and alcohol soluble extractives involve macerating a sample in water or alcohol and evaporating the filtrate to a constant weight.

1. COMPENDIAL METHODS FOR
EVALUATION OF CRUDE DRUG
AND HERBAL FORMULATION
PREPARED BY: SHRUTI PATEL
QA SEM I I
INDUBHAI PATEL COLLEGE OF PHARMACY & RESEARCH CENTRE, DHARMAJ

2. TABLE OF CONTENT
 What is crude drug?
 What is herbal drug?
 What is herbal formulation?
 General Compendial parameters for their evaluation?
 Methods for evaluation.

3. CRUDE DRUG
A crude drug is naturally occurring unprocessed
drug derived from plant, animal or
microorganisms intended for human or Veterinary
uses like medicine, nutritional supplements,
dietary fiber/ingredients or cosmetics.

4. HERBAL DRUGS
Herbal drugs are mainly whole, fragmented, or broken plants, cut
parts of plants, algae, fungi or lichen, in an unprocessed state,
usually in dried form but sometimes fresh. Certain exudates that
have not been subjected to a specific treatment are also
considered to be herbal drugs.
Herbal drugs are precisely defined by the botanical scientific
name according to the binominal system (genus, species, variety
and author).
Example: Neem leaf - Dried leaf of Azadirachta indica A. Juss.

5. HERBAL FORMULATIONS
Herbal drug formulations obtained by subjecting herbal drugs to
treatments such as extraction, distillation, expression, fractionation,
purification, concentration or fermentation.
Herbal drug preparations include, for example, extracts, essential
oils, expressed juices, processed exudates, and herbal drugs that
have been subjected to size reduction for specific applications, for
example herbal drugs cut for herbal teas or powdered for
encapsulation.
The herbal drug preparation thus obtained can also be converted to
formulations like tablet,capsules, aerosols ,liquid formulations with
single ingredient or mutiple ingredient.
e.g, Triphla tablets.

6. COMPENDIAL EVALUTION OF CRUDE DRUGS AND
HERBAL FORMULATIONS.
Parameters for evaluation of crude drugs:
 IDENTIFICATION
 TEST FOR FOREIGN MATTER
 LOSS ON DRYING
 MOISTURE CONTENT*
 RESIDUE ON IGNITION
 WATER AND ALCOHOL SOLUBLE EXTRACTIVES
 HEAVY METALS
 PESTICIDE RESIDUE TEST*
 MICROBIAL CONTAMINATION*
 TOTAL AFLATOXINS AND OCHRATOXINS
 ASSAY
 BITTERNESS VALUE
 SWELLING INDEX

7. METHODS FOR EVALUATION
PARAMETERS
1) Identification:
Is done for authentication of drug as well as to identify if any
adulterant is added.
Methods:
 Macroscopic characters
 Microscopic characters
 TLC/HPTLC
(It is performed as described In individual monograph)

8. 2) TEST FOR FOREIGN MATTER
Any organism, part or product of an organism, other than that named
in the specification and description of the plant material concerned.
Material not adhering to the medicinal plant materials, such as soil,
stones, sand, and dust.
Recommended procedure:
Weigh 100 –500 mg of the drug sample to be examined, or the
minimum quantity prescribed in the monograph. spread it out in a
thin layer.
The foreign matter should be detected by inspection with the unaided
eye or by the use of a lens (6x).
Separate and weigh it and calculate the percentage present.

9. 3) LOSS ON DRYING/TOTAL SOLIDS
 The test for loss on drying determines both water and volatile
matter in crude drug.
Loss on drying is the loss of mass expressed as % w/w and can be
determined by following procedure.
2.6.5. Total Solids
The term 'total solids' is applied to the residue obtained when
the prescribed amount of the preparation is dried to constant
weight under the conditions specified below.

10. Apparatus
Shallow, flat-bottomed, flanged dishes, about 7.5cm in
diameter and about 25 mm deep, made of nickel or other suitable
Metal of high heat conductivity and which is not affected by
boiling water.
Method
Weigh accurately or measure an accurate quantity of the substance under
examination stated in the individual monograph, place in a tared dish, evaporate
at as low a temperature as possible until the solvent is removed and heat
on a water-bath until the residue is apparently dry. Transfer to an oven and dry
to constant weight at 105°, unless otherwise stated in the monograph. Owing to
the hygroscopic nature of certain residues, it may be necessary to use dishes
provided with well-fitting covers and to cool in a desiccator.

11. 4) MOISTURE CONTENT*
By using Karl Fischer apparatus to be performed only in
dry powder drug or formulations
5) RESIDUE ON IGNITION
OR TOTAL ASH VALUE
“Remnant of the crude drugs after incineration contains mostly inorganic salts and non-volatile
inorganic components known as Ash”
Method:
Take a 2-3 gm of the air dried crude drug in the tared platinum or silica dish and
incinerate at temp. not exceeding 675 + 25°C.
Then Collect the residue on ash less filter paper which is Free from carbon, cool
and Weigh.
Calculate the % of Ash with Reference to air dried drug.
Muffle furnace can be used for this purpose.
Further the acid insoluble ash and water-soluble ash can also be done for
evaluation.

12. Method:
Take a 2-3 gm of the air dried crude drug (initial weight)in the
tared platinum or silica dish and incinerate at temp. not
exceeding 675 + 25°C.
Then Collect the residue on ash less filter paper which is Free
from carbon, cool and Weigh(final weight).
Calculate the % of Ash with Reference to air dried drug.
% total ash = (final weight / initial weight) * 100
Muffle furnace can be used for incineration at higher
temperatures.
Further the acid insoluble ash and water-soluble ash can also be
done for evaluation.

13. 6) WATER AND ALCOHOL SOLUBLE
EXTRACTIVES
The water soluble extractive value play an important role for the
evaluation of crude drugs.
 E.g water soluble extractive of ginger is expected to be in
the range of the 10% with respect to air dried material,
lowering of this extractive value indicates the addition of
exhausted material with the original drug.

14. METHOD I : WATER SOLUBLE EXTRACTIVES AND ALCOHOL
SOLUBLE EXTRACTIVES
Take 5 gm of air dried powder
Macerated with 100 ml of water/alcohol for 24 hours
Shaking frequently during the 1st 6 hours and allow to stand
for 18 hours
Thereafter filter rapidly
Evaporate 25 ml of the filtrate to dryness in a tared flat-bottomed
shallow dish, dry at 105°C and weight
Calculate the % of water soluble extractive with reference to
the air dried drug has to be calculated.

15. Method-II only for water soluble extractives
Take 5 gm of air dried powder in 50 ml water
Heated at 80°C in stopper flask
Shake well and allow standing for 10 min
Cool,
add 2gm of kieselguhr and filter
Transfer 5 ml of the filtrate to a tared evaporating dish
Evaporate solvent on a water bath
Continue drying for 30 minutes, finally dry in steam oven for 2
hours and weigh the residue
Calculate the % of water soluble extractive with reference to the
air dried drug has to be calculated

16.  Following tests are specified in pharmacopeias :
 7) HEAVY METALS: The limit for heavy metals is
indicated in the individual monographs in terms of ppm,
i.e., the part per million parts (by weight) of the substance
being examined. e.g., lead, mercury, arsenic.
 8)PESTICIDE RESIDUE TEST* : Pesticides are
chemicals derived from synthetic and natural sources which
are effective in small concentrations against pest.
 9)TOTAL AFLATOXINS AND OCHRATOXINS
 10)ASSAY : to check active ingredient as per individual
monograph

17. 11)MICROBIAL CONTAMINATION*:
this test is done to control the viable microorganism in drug or
product.
Methods:
1) Total viable count :
a. total plate count method
b. Membrane filtration method
c. serial dilution method
2) Tests for specified organisms(pathogens):
Such as Salmonella, pseudomonas, E.coli.
3) Test for yeast and molds (fungi).: which occurs only in water
soluble drugs.

18. References:
1) Indian Pharmacopeia 2010.
2) British Pharmacopeia 2012.
3) USP 36 NF 31
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