adulteration

2. Adulteration
It is a practice of substituting the original
crude drug partially or fully with other
substances which is either free from or inferior
in therapeutic and chemical properties or
Addition of low grade or spoiled drugs or
entirely different drug similar to that of original
drug substituted with an intention of
enhancement of profits.

3. Adulteration involves different conditions
such as
• Deterioration,
• Admixture,
• Sophistication,
• Substitution,
• Inferiority, and
• Spoilage.

4. • DETERIORATION is the impairment in the
quality of a drug.
• ADMIXTURE is the addition of one article
to another due to ignorance or carelessness,
or by accident.
• SOPHISTICATON is the intentional or
deliberate type of adulteration.

5.  SUBSTITUTION occurs when totally
different substance is added in place of
original drug.
 INFERIORITY refers to any sub-
standard drug.
 SPOILAGE deterioration due to the
attack of microorganisms.

6. Adulteration may take place by two ways:
- Direct or intentional adulteration
- Indirect or unintentional adulteration

7. Indirect or unintentional adulteration
• Unintentional adulteration which sometimes occurs
without bad intention of the manufacturer or supplier.
Sometimes in the absence of proper means of evaluation,
an authentic drug partially or fully devoid of the active
ingredients may enter the market.
• Factors such as geographical sources, growing
conditions, processing, and storage are all factors that
influence the quality of the drug.

8. Direct or intentional adulteration
• Direct or intentional adulteration is done intentionally which
usually includes practices in which an herbal drug is substituted
partially or fully with other inferior products.
• Due to morphological resemblance to the authentic herb, many
different inferior commercial varieties are used as adulterants.
• These may or may not have any chemical or therapeutic potential.
Substitution by “exhausted” drugs entails adulteration of the plant
material with the same plant material devoid of the active
constituents.

9. • This practice is most common in the case of volatile
oil-containing materials, where the dried exhausted
material resembles the original drug but is free of the
essential oils.
• Foreign matter such as other parts of the same plant
with no active ingredients, sand and stones,
manufactured artifacts, and synthetic inferior principles
are used as substitutes.

10.  Generally the drugs are adulterated by substitution with sub-standard
commercial varieties, inferior drugs, or artificially manufactured
commodities.
The following types of adulteration are common
1. SUBSTITUTION WITH SUB-STANDARD COMMERCIAL
VARIETIES
2. SUBSTITUTION WITH SUPERFICIALLY SIMILAR INFERIOR
DRUGS
3. SUBSTITUTION WITH ARTIFICIALLY MANUFACTURED
SUBSTANCES
Types of adulteration

11. 4. SUBSTITUTION WITH EXHAUSTED DRUG
5. USE OF SYNTHETIC CHEMICALS
6. PRESENCE OF VEGETATIVE MATTER FROM
THE SAME PLANT
7. HARMFUL ADULTERANTS
8. ADULTERATION OF POWDERS

12. 1. SUBSTITUTION WITH SUB-
STANDARD COMMERCIAL
VARIETIES
• The adulterants here may resemble the original
crude drug in morphological, chemical, or
therapeutic characters, but are sub-standard in
nature and hence are cheaper in cost. This is a
rather most common practice of adulteration.

13. e.g. Strychnous nux-blanda or S.potatorum in
place of S.nux-vomica,
Capsicum annuum in place of C.minimum,
Indian senna is substituted with arabian senna
or dog senna,
Medicinal ginger is substituted with inferior
varieties of African, Japanese, or Cochin
ginger.

14. 2. SUBSTITUTION WITH
SUPERFICIALLY SIMILAR INFERIOR
DRUGS
 These inferior drugs used may or may not be having any chemical or
therapeutic value as that of original drug.
 Due to their morphological resemblance to the authentic drug, they are
used as adulterants.
Examples
 Belladonna leaves are substituted with Ailanthus leaves,
 Saffron is admixed with dried flowers of Carthamus tinctorious, and
 Bees wax is substituted with Japan wax.

15. 3. SUBSTITUTION WITH
ARTIFICIALLY MANUFACTURED
SUBSTANCES
 It has been also observed that substances artificially
prepared to resemble the original drug are used as
substitutes. This practice is followed for much costlier
drugs.
 e.g., Compressed Chicory in place of coffee,
 Yellow coloured paraffin wax for bees wax,
 Properly cut and shaved basswood for nutmeg.

16. 4. SUBSTITUTION WITH EXHAUSTED
DRUG
• The same drug is admixed but is devoid of any medicinally
active constituents as they are already extracted out.
• This practice is more common in case of volatile oil
containing drugs like fennel, clove, coriander, caraway etc.
• Sometimes natural characters of exhausted drugs like
colour and taste are manipulated by adding other additives
and then it is substituted.

17. oe.g. Exhausted gentian made bitter with
aloes,
oArtificial colouring of exhausted saffron,
etc.

18. Besides these common practices, sometimes
other methods are also employed like use of
synthetic chemicals to enhance the natural
character as in case of
 addition of benzyl benzoate to balsam of peru,
 citral to citrus oils like oil of lemon and orange
oil, etc.
5. Use of synthetic chemicals

19. 6. PRESENCE OF VEGETATIVE
MATTER FROM THE SAME PLANT
• Sometimes, the other miniature plants growing along with
medicinal plants are admixed with the authentic drug, due to
their resembling colour, odour, and in some cases
constituents.
• The lower plants like moss, liverworts, and epiphytes
growing on bark portion are mixed with cascara or cinchona.
• The stem portions are mixed along with leaf drugs like
stramonium , lobelia and senna.

20. 7. HARMFUL ADULTERANTS
o Sometimes the waste from the market are collected and admixed
with the authentic drug. This is particularly noticed for liquids
or unorganized drugs.
o The examples like pieces of amber coloured glass in colophony,
limestones in asafoetida, lead shot in opium, white oil in coconut
oil, cocoa butter mixed with stearin or paraffin.
o The addition of rodent feacal matter to cardamom seed is a very
harmful adulteration.

21. 8. ADULTERATION OF POWDERS
Besides the entire drug, the powdered forms are frequently
found to be adulterated.
Examples
Dextrin in ipecacuanha,
Powered liquorice or gentian admixed with powdered olive
stones
Exhausted ginger powder in powdered colocynth or ginger.

22. Evaluation of Crude Drugs
• Evaluation of drug means confirmation of its identity and
determination of its quality and purity and detection of nature of
adulteration.
Types of Evaluation
• Organoleptic evaluation
• Microscopic evaluation
• Physical evaluation
• Chemical evaluation
• Biological evaluation

23. Organoleptic evaluation
 It means evaluation of drug by the organs of sense
(skin, eye, tongue, nose and ear) or macroscopic
evaluation and it includes evaluation of drugs by
I. Color,
II.Odor,
III.Taste,
IV.Size,
V.Shape
VI. and special feature, like touch, texture etc.

24.  It is the technique of qualitative evaluation based on the study of
morphological and sensory profile of whole drugs.
 eg. The fractured surfaces in cinchona, quillia, cascara barks and
quassia wood are important characteristics.
 Aromatic odour of umbelliferous fruits and sweet taste of
liquorice are the examples of this type of evaluation where odor
of drug depends upon the type and quality of odourous principles
(volatile oils) present.

25. • Shape of drug may be cylindrical (sarsapilla), subcylindrical
(podophyllum), conical (aconite), fusiform (jalap) etc, size
represent length, breadth, thickness, diameter etc.
• Color means external color which varies from white to brownish
black are important diagnostic characters.
• Taste is specific type of sensation felt by epithelial layer of
tongue. It may be acidic (sour), saline (salt like), saccharic
(sweetish), bitter or tasteless (possessing no taste).

26. The general appearance (external marking) of the crude drug
often indicates whether it is likely to comply with prescribed
standard like
 furrows (alternate depression or valleys),
 wrinkles (fine delicate furrows),
 annulations (transverse rings),
 fissures (splits),
 nodules (rounded outgrowth),
 scars (spot left after fall of leaves, stems or roots).

27. Microscopic evaluation
It involves detailed examination of the drug and
it can be used to identify the organized drugs by
their known histological characters.
It is mostly used for qualitative evaluation of
organized crude drugs in entire and powder
forms with help of microscope

28. • Qualitative microscopy
Using microscope detecting various cellular
tissues, trichomes, stomata, starch granules,
calcium oxalate crystals and aleurone grains are
some of important parameters which play
important role in identification of certain crude
drug.

29. • Quantitative microscopy
Quantitative aspects of microscopy includes
study of stomatal number and index, palisade
ratio, vein-islet number, size of starch grains,
length of fibers etc which play important role
in the identification of drug.

30. Qualitative microscopy
Stomata
There are several types of stomata, distinguished by the forms and arrangement of
the Surrounding cells (Subsidary cells), e.g.
(a) Anomocytic (Ranunculaceous) irregular celled: Digitalis
(b) Anisoytic (Cruciferous) unequal celled: Datura
(c) Diacytic (Caryophyllaceous) perpendicular celled: Mentha
(d) Paracytic (Rubiaceous) parallel celled: Senna
(e) Actioncytic: 4 or more subsidary cells,elongated radially to stomata- Mucaceae
(f) Cyclocytic: 4 or more subsidary cells,arranged in narrow ring around stomata-
Palmae

32. Trichomes
• Trichomes are divided and subdivided as follows-
(i) Covering Trichomes
(a) Unicellular Trichomes: Nux vomica, Cannabis
(b) Uniseriate Multicellular Unbranched Trichomes: Datura
(c) Biseriate Multicellular unbranched Trichomes: Calendula
officinalis
(d) Multiseriate Multicellular unbranched Trichomes: Male fern
(e) Multicellular branched Trichomes: Verbascum Thapsus

33. (ii) Glandular Trichomes
(a) Unicellular Glandular Trichomes: Vasaka
(b) Multicellular Glandular Trichomes: Digitalis
purpurea
(iii) Hydathode Trichomes: Piper betal

34. Quantitative Microscopy
It involves different parameters like
Palisade Ratio: It is defined as average number
of palisade cells beneath each epidermal cell.
e.g. Atropa belladonna (6-10),
Digitalis Lanata (2.5-6.5)

35. • Stomatal Number : It is defined as average number of
stomata per square millimeter area of epidermis.
e.g.: Atropa belladonna: {6.0-14-37.5 (Upper Surface), 62.5-93-
174 (lower Surface)}.
• Stomatal Index: It is the percentage which the number of
stomata forms to the total number of epidermal cells. It is
calculated by,

36. Where, S.I = Stomatal Index;
S = Number of stomata per unit area;
E = Number of Epidermal cells in the same unit area.
e.g. Atropa belladonna:- 2.3-3.9-10.5 (Upper Surface),
20.2 - 21.7 - 23.0 (Lower Surface)
Digitalis Purpurea - 1.6-2.7-4.0 (Upper Surface);
19.2- 25.2 (lower Surface).

37. Vein Islet: The small areas of green tissue outlined by the
veinlets are termed as vein islet.
• Vein Islet Number:
It is defined as average number of Vein Islet per square
millimeter of the leaf surface midway between midrib
and the margin.
i. Digitalis Lanata — 2.0-8.0
ii. Digitalis Purpure — 2.0-5.5

38. • Vein terminations are the ultimate free terminations of a
veinlet or branch of a vienlet.
Vein Termination Number:
It is defined as average number of Vein terminations per square
millimeter of the leaf surface midway between midrib and the
margin.
• Atropa belladonna — 6.3-10.3
• Atropa acuminate — 1.4-3.5

39. Physical evaluation
Physical constants are sometimes taken into consideration
to evaluate certain drugs.
These include
• moisture content,
• specific gravity,
• optical rotation,

40. • Refractive index,
• melting point,
• viscosity and
• solubility in different solvents.

41. • All these physical properties are useful in identification and
detection of constituents present in plant.
• Ash values
– Total ash
– Water soluble ash
– Acid insoluble ash
– Sulphated ash
• Fluorescence analysis
• Foreign matter

50. Determination of Total Ash
• Incinerate about 2 to 3 g accurately weighed, of
the ground drug in a tarred platinum or silica dish
at a temperature not exceeding 450ºC until free
from carbon, cool and weigh. Calculate the
percentage of ash with reference to the air-dried
drug.

51. Drugs Total ash (% w/w)
Aloes Not more than 5 %
Ashoka Not more than 11%
Amla Not more than 7 %
Nutmeg Not more than 3 %
% Total ash value = Wt. of total ash
x 100
Wt. of crude drug taken

52. Acid insouble ash
• Test measures the amount of silica present, especially as sand
siliceous earth.
• The obtained total ash was boiled with 25 ml of 2N HCl for 5 min.
The insoluble ash was collected on ash less filter and washed with
hot water. The insoluble ash was transferred into pre-weighed
silica crucible, ignited, cooled and weighed. The procedure was
repeated till the constant weight was obtained. The percentage of
acid insoluble ash was calculated with reference to the air dried
drugs.

53. Drugs Acid insoluble ash (%w/w)
Agar Not more than 1.0
Amla Not more than 2.0
Bael Not more than 1.0
Wt. of acid insoluble ash
% Acid insoluble ash value = x 100
Wt. of crude drug taken

54. Determination of water soluble ash value
• The total ash obtained was boiled with 25 ml of chloroform water
for five min. The insoluble matter was collected on a ash less filter
paper & and washed with hot water. The insoluble ash was
transferred into pre-weighed silica crucible, ignited for 15 min at a
temperature not exceeding 450°C, cooled and weighed. The
weight of the insoluble matter was subtracted from the weight of
total ash. The percentage of water soluble ash was calculated with
reference to the air-dried sample drug.

55. Wt. of total ash - Wt. of water insoluble ash
% Water soluble ash value =
x 100
Wt. of crude drug taken

56. Determination of Sulphated ash value
• Silica crucible was heated to redness for 10 minute, allowed to
cool in a desiccator and weighed. The total ash obtained was taken
in the crucible and weighed accurately. It was ignited gently at
first, until the substance is thoroughly charred. the residue was
cooled, moistened with 1 ml of conc. Sulphuric acid, heated gently
until white fumes are no longer evolved and ignited at 450°C
temperature until all black particles have disappeared.

57. The crucible was allowed to cool, a few drops of
conc. sulphuric acid was added and heated.
Ignited as before, allowed to cool and
weighed. The percentage of Sulphated ash was
calculated. Wt. of Sulphated ash
% Sulphated ash value = x 100
Wt. of crude drug taken

58. DETERMINATION OF FOREIGN
MATTER
• Weigh 100 –500 g of the drug sample to be
examined or the minimum quantity prescribed in
the monograph, and 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.

59. Chemical evaluation
• Most of drugs have definite chemical constituents to
which their biological or pharmacological activity is
attributed.
• Qualitative chemical test are used to identify certain drug
or to test their purity.
• The isolation, purification, identification of active
constituents is based on chemical methods of evaluation.

60. Some of these are useful in evaluation of
 resins (acid value, sulphated ash),
 balsams (acid value, saponification value and bester values),
 volatile oils (acetyl and ester values) and
 gums (methoxy determination and volatile acidity).
Preliminary phytochemical screening is a part of chemical
evaluation.
These qualitative chemical tests are useful in identification of
chemical constituents and detection of adulteration.

61. Chemical evaluation scheme
Extraction of crude drug powder (successive solvent
extraction)
Preliminary phytochemical screening
Chromatography & Spectroscopy

62. Step 1 – Preliminary
phytochemical screening
Major phytochemicals
• Alkaloids
• Glycosides
• Flavonoids
• Steroids
• Phenols
• Tannins
• Resins
• Amino acids
• Carbohydrates
• Gums
• Volatile/essential oils
• Fixed oils
• Terpenoids
• Saponins

63. Test for alkaloids
i) Mayer's test (Potassium Mercuric Iodide): The acid layer
with few drops of Mayer's reagent gives a creamy white
precipitate.
ii) Wagner's Tests (Solution of Iodine in Potassium
Iodide): The acid layer with few drops of Wagner's
reagent gives reddish brown coloured precipitate.
iii) Hager's Test (Saturated solution of picric acid): The
acid layer with Hager's reagent gives yellow precipitate.
iv) Dragendroff's test (Solution of Potassium Bismuth
Iodide): Acid layer with few drops of Dragendroff's
reagent gives reddish brown precipitate.

64. Tests for steroids
i) Salkowski Tests: Chloroform solution of the
extract when shaken with concentrated sulphuric
acid and on standing yields red colour.
ii) Lieberman Burchard tests: Chloroform
solution of the extract with few drops of acetic
anhydride and one ml of concentrated sulphuric
acid from the sides gives reddish ring at the
junction of 2 layers.

65. Tests for Triterpenes
i) Salkowski test: Chloroform solution of the
extract when shaken with concentrated sulphuric
acid, lower layer turns to yellow on standing.
ii) Lieberman Burchard test: Chloroform
solution of the extract with few drops of acetic
acid and one ml concentrated sulphuric acid
gives deep red at the junction of 2 layers.

66. Test of Tannins
1. Goldbeater's skin test
Goldbeater's skin is a prototype of untanned fresh skin
of an animal & is obtained as a membrane from the
intestine of Ox. This membrane is treated with HCl;
rinsed with distilled water and place in the tannin
solution 5 min. Washed with distilled water and
transferred into a solution of FeSO4. A brown or black
colour on the skin denotes the presence of tannins.
 Goldbeater's skin is a membrane prepared from the
intestine of the ox and behaves similarly to an untanned
hide.

67. 2- Phenazone Test:
To 5 ml of aqueous solution of tannin containing
drug, add 0.5 g of sodium acid phosphate. Warm
the solution, cool and filter. Add 2 % phenazone
solution to the filtrate. All tannins are
precipitated.
3- Gelatin Test:
To a 1 % gelatin solution, add little 10 % sodium
chloride. If a 1 % solution of tannin is added to
the above gelatin solution, tannins cause
precipitation of gelatin from solution.

68. Chemical Test for Volatile oil
• Presence of volatile of oil can be detected by
following Test.
1) Take thin section of the drug & add a drop of
tincture alkana. Red color is produced which
indicates presence of volatile oil.
2) Take a thin Section of drug & add alcoholic
soln of Sudan III – Red color, which indicate
presence of volatile oil.

69. Test for Flavonoid
a) Alkaline reagent test: Extract was treated with
10 % NaOH solution; formation of intense
yellow color indicates presence of Flavonoid.
b) Mg turning test: Extract were treated with Mg
turning and add conc. HCl to this solution add
5ml of 95 % ethanol, formation of crimson red
colour indicates Flavonoid.
c) Zinc test: 2 ml extract were treated with Zn dust
and conc. HCl, development of red colour
indicates presence of Flavonoid

70. d) Ferric chloride test: Alcoholic solution of
the extracts mixed with few drops of neutral
ferric chloride solution gives green colour.

71. • Test for Phenolic compounds
• The extract (500 mg) was dissolved in 5 ml of
distilled water. To this, few drops of neutral 5%
ferric chloride solution were added. A dark
green color indicated the presence of phenolic
compounds

72. • Test for gum and mucilage
• About 10ml of the extract was slowly added to
25ml of absolute alcohol under constant
stirring. Precipitation indicates the presence of
gum and mucilage.

73. • Test for fixed oils and fats
• A drop of concentrated extract was pressed in
between two filter papers and kept
undisturbed. Oil stain on the paper indicates
the presence of oils and fats

74. • Test for glycoside
• Glycosides are compounds which upon
hydrolysis give rise to one or more sugars
(glycones) and a compound which is not a sugar
(aglycone or genuine).
• To the solution of the extract in glacial acetic
acid, few drops of ferric chloride and
concentrated sulphuric acid are added, and
observed for a reddish brown coloration at the
junction of two layers and the bluish green color
in the upper layer.

75. • Test for amino acids
a) Ninhydrin test
To 1ml of sample, add 5drops of Ninhydrin
Reagent. Heated in a boiling water bath for 2
min. A purple color indicates the presence of
amino acids.
b) Xanthoproteic test
To 3ml of the sample, add 1ml of concentrated
nitric acid and heated for 3min. Then cooled
and added 0.5 ml of NaOH. Reddish orange
color indicates the presence of aromatic amino
acids.

76. • Million’s test
• To 1ml of sample, add 1ml of Million’s
reagent and heated for 3 minutes. Then 1%
sodium nitrate is added. Red color formed
indicates the presence of amino acids.

77. Tests for Saponins
i) Foam test: A small amount of extract is shaken
with little quantity of water. The foam produced
persists for 10 min. It confirms the presence of
saponins.
ii) Haemolysis test: To 2 ml normal saline in 2 test
tubes, 2 ml distilled water is added to one and two
ml of 1 % extract to the other five drops of blood
is added to each test tube and gently mixed with
the content. Haemolysis observed under the
microscope in the tube containing the extracts
indicates the presence of saponin.

78. Tests for Carbohydrates
• MOLISCH TEST
• Take 2 ml of carbohydrate solution in a clean
and dry test tube. Add 2 drops of ethanolic
Alpha Naphthol (Molisch reagent) and mix.
Incline the test tube and add carefully 2 ml of
concentrated sulphuric acid along the side of
the test tube so as to form 2 layers.
• An appearance of reddish violet or purple
colored ring at the junction of two liquids is
observed in a positive Molisch test.