Cannabis consists of the dried flowering and fruiting tops of the
pistillate plant of Cannabis sativa Linn. (Fam. Cannabinace¾), an
annual dioecious herb indigenous to Central Asia and the Northern and
Western Himalayas, and cultivated mainly in tropical districts of
India, Africa, and North America.
Cannabis occurs in flattened, dull green masses which remain more or
less compacted together by the adhesive resinous secretion. The tops
vary in length from about 3 to 30 centimetres, the smaller tops being
preferred; they consist of the upper part of the stem with ascending
branches, which are longitudinally furrowed and bear numerous covering
and glandular trichomes. The leaves are alternate and consist of simple
or palmately compound bracts, each having two linear stipules and
bearing in its axil two bracteoles, each of which subtends a single
pistillate flower or a more or less developed fruit occasionally
containing an oily seed. The taste is very slight and the odour
somewhat heavy and narcotic.
The diagnostic microscopical characters are the conical, curved,
unicellular cystolith-trichomes with enlarged bases; the similar but
more slender trichomes without cystoliths; the numerous, usually
8-celled, rosette-shaped, glandular trichomes with either unicellular
or multiseriate pedicels; the bracteoles with very numerous small
cluster-crystals of calcium oxalate; the red stigmas with long
cylindrical papill¾ laticiferous tubes with brown contents; occasional,
more or less lignified, phloem fibres from the stem, and brown,
thick-walled, pitted cells from the palisade layer of the pericarp.
Cannabis contains a soft, brown resin (cannabinone), the chief
constituent of which is cannabinol, C21H26O2, a viscid, reddish oil,
possessing a powerful narcotic action, but resinifying and becoming
less active on exposure to air; choline, and traces of volatile oil,
fat, and wax are also present. Cannabis yields to alcohol (90 per cent)
from 10 to 22 per cent of extractive. The ash is about 15 per cent. The
following test has been used for the identification of cannabis: Shake
0.1 gramme in powder with 5 millilitres of light petroleum for three
minutes and filter; to 1 millilitre of the filtrate add 2 millilitres
of a 15 per cent w/v solution of hydrogen chloride in dehydrated
alcohol; at the junction of the two liquids a red colouration appears,
and, after shaking, the upper layer becomes colourless and the lower
layer acquires an orange-pink colouration which disappears on the
addition of one millilitre of water.
Varieties: Tinctures of cannabis, prepared from African, American,
German, and Indian varieties of the drug, when examined by oral
administration to cats appear to possess about the same degree of
activity, and this activity is not destroyed by long storage of the
drug in a dry condition.
Standard: Cannabis contains not more than 10 per cent of fruits, large
foliage leaves, and stems over 3 millimetres in diameter, and not more
than 2 per cent of other foreign organic matter. Acid-insoluble ash,
not more than 5 per cent. When a mixture of 10 grammes of finely
powdered cannabis and 100 millilitres of alcohol (90 per cent) is
shaken occasionally during twenty-four hours and then filtered, 20
millilitres of the filtrate, evaporated in a flat-bottomed dish, yields
a residue weighing, when dried at 100 degrees, not less than 0.20
gramme. Cannabis indic¾ herba I.A. consists of the tops, in flower and
in fruit, of the female plant cultivated in the East Indies.
Cannabis, in powder (Pulvis Cannabis : Pulv. Cannab.), contains the
constituents and possesses the diagnostic microscopical characters of
Cannabis, and complies with the limits for acid-insoluble ash and
residue on extraction with alcohol (90 per cent) of the unground drug.
Action and Uses: Cannabis acts chiefly on the central nervous system.
It first produces excitement with hallucinations, a feeling of
happiness and indifference to surroundings, this stage being followed
by deep sleep. The hallucinations include inability to estimate time
and space. In the East the hemp is smoked and almost immediately
produces symptoms of pleasurable excitement, followed by depression and
lethargy. Cannabis is used as an anodyne sedative or hypnotic in mania,
spasmodic coughs, phthisis, asthma, and dysmenorrhoea. It has been used
in the treatment of chorea and paralysis agitans. It does not produce
constipation or loss of appetite. Cannabis is usually administered as
the extract in pills, or as tincture. In cases of poisoning the stomach
should be evacuated and the usual methods adopted to prevent collapse
and respiratory failure.
CANNABIN® TANNAS: Cannabine tannate is a brownish powder which may be
obtained from an aqueous extract of cannabis by precipitation with
tannic acid. It has been used as a hypnotic in nervous insomnia, in
dysmenorrhoea and in menorrhagia. Dose - 0.25 to 0.5 gramme (4 to 8
grains).
CANNABINONUM: Cannabinone, the brown resin obtained from cannabis, has
been used as a hypnotic in hysteria and insomnia. Dose - 0.016 to 0.06
gramme (1/4 to 1 grain).
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(Ext. Cannab.)
Extract of Cannabis
Dose: 0.016 to 0.06 gramme (1/4 to 1 grain).
In making this preparation the alcohol (90 per cent) may be replaced by
industrial methylated spirit diluted so as to be of equivalent alcoholic
strength, provided that the law and the statutory regulations governing the
use of undustrial methylated spirit are observed.
This extract replaces the Extractum Cannabis Indic¾ of the British
Pharmacopoeia, 1914, which was prepared in the same way from Indian cannabis
(Cannabis Indica).
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