WHO monographs on selected medicinal plants - travolekar.ru

Cortex Salicis
medullary rays; thickened and suberized cork cells. Groups of brownish
collenchyma from the bud may be present. Twigs show, additionally, fragments
of lignified fibres and vessels from the xylem (2, 4).
General identity tests
Macroscopic and microscopic examinations and thin-layer chromatography
(1, 2, 4).
Purity tests
Microbiological
Tests for specific microorganisms and microbial contamination limits are
as described in the <strong>WHO</strong> guidelines for assessing quality of herbal medicines
with reference to contaminants and residues (12).
Foreign organic matter
Not more than 3% of twigs with a diameter greater than 10 mm, and not
more than 2% other foreign matter (1, 2, 4).
Total ash
Not more than 10% (1, 2, 4).
Acid-insoluble ash
Not more than 3% (1, 2).
Water-soluble extractive
Not less than 10% (1, 2).
Alcohol-soluble extractive
To be established in accordance with national requirements.
Loss on drying
Not more than 11% (4).
Pesticide residues
The recommended maximum limit of aldrin and dieldrin is not more than
0.05 mg/kg (4). For other pesticides, see the European pharmacopoeia (4)
and the <strong>WHO</strong> guidelines for assessing quality of herbal medicines with
reference to contaminants and residues (12) and pesticide residues (13).
Heavy metals
For maximum limits and analysis of heavy metals, consult the <strong>WHO</strong>
guidelines for assessing quality of herbal medicines with reference to contaminants
and residues (12).
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