NIS - libdoc.who.int - World Health Organization

Styli cum stigmatis Zeae maydis
Microscopic characteristics
Epidermal cells rectangular, often extended into multicellular trichomes
200–800 µm long, the basal portion consisting of 2–5 cells and the upper
portion usually unicellular; multicellular and multiseriate trichomes,
some of which are bluntly toothed; purplish red parenchymatous cells
containing red colouring matter; two vascular bundles containing narrow
tracheids with spiral or annular thickening (1, 5, 28, 29).
Powdered plant material
Yellow powder with a slight odour and an insipid taste; rectangular epidermal
cells often extending into multicellular trichomes; fragments of
trichomes; parenchymatous cells with red contents (28).
General identity tests
Macroscopic and microscopic examinations (1).
Purity tests
Microbiological
Tests for specific microorganisms and microbial contamination limits are
as described in the WHO guidelines on quality control methods for medicinal
plant materials (30).
Chemical
No information available.
Foreign organic matter
Not more than 0.5% of organic matter (1). Brownish styles and stigmas
or their fragments, not more than 3%. For cut drug: not more than 5% of
fragments of drug having a length more than 7 mm and not more than 1%
of fragments of drug having a length and diameter less than 0.2 mm (1).
Total ash
Not more than 8% (29) or not more than 7% (1).
Acid-insoluble ash
Not more than 2% of ash insoluble in concentrated hydrochloric acid (29)
or not more than 2.5% of ash insoluble in 10% hydrochloric acid (1).
Sulfated ash
No information available.
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