Page 232 - PG 101-Course notes مذكرة النظري 24-25 with spec

Medicinal plants (PG 101) Level 1 Clinical Pharmacy-PharmD

II- Biological Factors:

• The biological factors producing deterioration of most drugs are bacteria, molds,

fungi, insects, and mites. These may change the physical properties of the drug such

as color and texture. Molds and fungi usually attack drugs rich in nutritive substances

such as bulbs, corms, roots and rhizomes if they are not stored properly. This may

lower the active constituents. Insects attack nearly all drugs in powdered form,

rendering them unsuitable for preparation of standard extracts. Insects should be

destroyed before storage of the drugs. This is done by one of the following methods:

a. Heating the drugs to about 60 to 65 ˚C to kill the egg insects. In some cases, heating

may affect the active constituents of some drugs, so this method is not suitable for all

drugs.

b. Fumigation of drugs by using various volatile insecticides in closed areas such as

carbon tetrachloride, carbon disulphide, a mixture of methylene oxide and carbon

dioxide. Most fumigants do not kill the eggs, so the drug must be fumigated at

intervals. Fumigants must be applied carefully because they are poisonous.

c. Liming: This is used for few drugs such as ginger and nutmeg. The drug is immersed

in slaked lime or sprinkled with quick lime. This will block the respiratory system

of insects and larvae, so die after time.

o Rodents also cause much spoilage of crude drugs during storage if the drugs are

stored in paper, cloth, cardboard, or wooden containers. The presence of the hairs and

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