ADULTERATION OF CRUDE DRUGS

• DEFINTION: Any substance which does not comply to the requirement of the pharmacopoeia is an adulterant.

• Therefore Adulteration can be defined as anything causing debasement of a drug.

• Adulteration can occur through various ways or conditions and these include:

1. Faulty collection of the drug2. Improper preparation of the drug for the market 3. Poor storage conditions 4. Deliberate.

1. Faulty Collection Collection of the drug from the correct identified plant but

done during improper time of collection.

That is the drug might not be collected during the right season, proper age, and correct stage of development.

a) Season: It governs both the type and amount of the chemical constituents

• Solanaceous plant: Are usually collected in summer

• Colchicum (colchicine) is normally collected in summer

• Rauwolfia (reserpine) and Ephedra (ephedrine) are collected in autumn

b) Age: The chemical constituents reach their peak at a certain age

• Crude drug should therefore be collected during a appropriate age

• The stem bark Holarrehna antidysentrica (H. pubescens, Apocynaceae) used in dysentery it contains steroidal alkaloids, maximum concentration at 8-12 years

• Rauwolfia and Belladonna are collected when 4 years old

• Rhubarb 6-10 years

c) Stage of Development • Cloves - Eugenia caryophyllus (Szygium aromaticum): Have

maximum concentration of the essential oil in bud stage when the lower part of the bud turns crimson in colour.

• Pyrethrum are partially opened flowers of Chrysanthemum

cinerariifolium when the flowers are allowed to expand the concentrations of the pyrethrins falls

• Umbelliferous fruits consists of nearly ripe dried fruits

• Chiretta Swertia chirata contains a bitter substance chiratin should be collected at a flowering stage

• Cannabis- pistillated plants of Cannabis sativa Fertilization leads to a fall in resin content falls. Male plants are removed as soon as the sex is determined. Plants with fruits are said to be of inferior quality.

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Collection of the drug, with less valuable parts of the plant, along with the required part which should be collected

• Clove stalk and mother cloves in cloves can be collected together with cloves.

• These structures, contain less volatile oils.

• A limit is normally given for them.

Collection of the drug together with allied species of inferior quality

• Nux-vomica is the dried ripe seeds obtained from Strychnos nux-vomica seed from allied species of S. potatorum or S. nux-blanda are of inferior grade.

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• S. potatorum is completely devoid of the chemical constituents found in nux-vomica (strychnine or brucine).

• Platango ovata commonly known as Isapgol is an important mucilage containing drug employed as a laxative.

• Imported in USA from India and mainly used in USA as a laxative.

• The seeds are the one employed.

• Seeds of P. lanceolata does not have the laxative effect

Collection of the drug together with plant part from a different species or genus

• Can be accidental or deliberate.

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• Salvia aegyptiaca is used to adulterate Platango ovata

• Tragacanth (Astragalus gummifer) in powdered form is normally adulterated with Sterculia urens (Indian Tragacanth known as Karaya gum.

• In powdered form the two cannot be differentiated,

adulteration can be accidental or deliberate.

• Leaves of Digitalis purpurea in European market, the leaves of Verbascum thapsus and Primula vulgaris are commonly used as adulterants can be accidental or deliberate.

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• Atropa belladnna is adulterated by Scopolia corniolica accidental or deliberate.

2. Improper preparation of the drug for the markets:

• Non - removal of associated structures• Non - removal of the inert part of the drug• Negligence in drying procedure.

Non - removal of associated structures• Associated structures need to be removed during preparation

of the drug

• Aconite and Pyrethrum Limit of stem is 5%

• Hyosyamus stem over 5 mm diameter should not exceed 3%.

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• Cannabis: Large foliage leaves, fruits and stem of diameter >3mm should not exceed 10%.

• Ergot is a dried sclerotium of the fungus Claviceps purpurea.

• The fungus grows on the flowers of the rye plant.

• Flowers, fruits and seeds of the rye should not exceed 2%.

• Picrorhiza rhizome is used as one of the effective drug it has a cholagogue effect.

• It is used in jaundice and liver disorders.

• The active principles kutkin are absent from the rootlets hence rootlets should be removed.

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• Benzoin: Are balsams obtained by scrubing off the tears on the

surface of a plant.

• Vegetable materials should be removed

• They give a bad appearance and cause break down of balsam into balsamic acids.

• Epiphytes like moss, liverworts and lichens can also occur in excessive amounts in bark drugs such as cinchona and cascara

Non removal of the inert part of the plant structure.

• Ginger: The oleoresin is present in the inner sections revealed the cross – section of Ginger.

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• Outer coat is devoid of the oleoresin should be removed, the part remaining is dried and this gives a good appearance to the drug

• Cinnamon: This is the dried inner bark of Cinnamomum zeylanicum.

• The outer layer of the bark is devoid of the volatile oils normally the bark in peeled before drying

• Squill: According to the pharmacopeia the bulbs should be devoid of the dried membranous outer scale because this part does not contain the active principles

• Orange peel: The white fibrous spongy material does not contain any volatile oils, Hence the orange peel should be freed from this spongy material

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Negligence in drying process.• This is seen in Digitalis and Valerian• The leaves should be dried immediately after collection at

60oC and in dark.

• If not dried immediately then Purpurea glycoside A and B will undergo decomposition to give triglycosides

• Valerian: Major Principle is an ester bornylisovalerinate.

• The fresh drug does not have any odour, however, if not dried immediately after collection the enzymes present can decomposes the ester into an acid with a very strong aroma.

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3. Poor storage conditions

• The following example indicates how poor storage of a drug can lead to a substandard drug.

• Opium: If kept in the open loss of morphine occurs

• Digitalis: Should be stored with a dehydrating agent to prevent enzymic reactions

• Biological preparations: Need to be stored at low temperature so as to preserve their activities

• Squill: Should be stored in a tightly closed container so as to prevent the mucilage contain in the drug to absorb moisture from the air which could lead to activation of enzymic actions

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• Cannabis: Loses its activity if stored for a long time even if all precautions are taken.

• The Pharmacopoeia specifies that the drug should not be stored for more than 2 years

• Ergot: Should be defatted before storage. The drug contain 30% of the fatty material.

• In presence of moisture the fatty material become rancid producing acids which leads to the decomposition of ergotamine.

• Moisture content of the drug should not be more than 6%.

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4. Deliberate adulteration: Sometimes the drug is substituted with the exhausted drugs.

This is applicable incases v. oil containing drugs.

• This is only possible where exhaustion does not alter the appearance of the drug.

• The drug can be subjected to steam distillation then dried up ready for the market.

• Sometimes the colour can be slightly dark.

• Common for drugs from Umbelliferous, Ginger, Cardamon, Cloves, benzoin

• Gentian its bitter restored by using aloes

• Saffron (dried Sitigma and the top of the style of Crocus sativus ) and rose petals are coloured by artificial dyes

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Drug is weighed with inert materials

• Was done in case of opium

• The drug was mixed with lead pieces to increase weight. No longer done nowadays because the drug is under government control

• Large mass of stones (volcanic lava), were added to Liquorice

• Also pieces of limestone in Asafetida ( latex of rhizome or tap roots of various sp. of Ferula

Fictitious materials or manufacture’s substitute (Sophistication)

• Here, materials are artificially manufactured so as to simulate the general form and appearance of various drugs

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• Ergot from Portugal was adulterated up to 25% by small masses of dough moulded to correct size, shaped and colored by dipping in red then (blue) writing ink.

• Coffee substituted by compressing powdered chicory (roasted root of Cichorium intybus) to the shape of coffee berries.

• Beeswax substituted by yellow paraffin wax.

• Honey by artificial invert sugar

• Cheap cotton seed oil substituted for Olive oil.

• Nutmeg: These are dried kennels of the seeds of Myristica fragrans

• During the process of preparation of the drug the broken pieces are mixed with clay to give the shape of a nutmeg

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Addition of synthetic principles to fortify products

• Addition of citral to oil of lemon or benzylbenzoate to balsam of Peru

Addition of powdered waste material of suitable colour and density

• Olive stone powder added to gentian, Liquorice or pepper.

• Hazel shells added to cinnamon.

• Powdered guaiacum wood added to nux -vomica

• Dextrins to powdered ipecac

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• Why adulterate?

• When the drug is scarce

• When the price is high

• People want to make more money

• Read about:

• Spoilage

• Inferiority

• Deterioration.

How to determine if a drug is adulterated and to which extent?

• Many methods/test are employed especially those applicable in monograph which may include the following

• Examination of both macroscopical and microscopical characters

• Determination of extractives, ash values, assays and other tests applicable in the monograph of crude drugs

• Quantitative microscopy

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