QUININE HYDROCHLORIDE

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QUININE HYDROCHLORIDE



Prepared at the 41st JECFA (1993), published in FNP 52 Add 2 (1993)
superseding specifications prepared at the 39th JECFA (1992), published
in FNP 54 Add 1 (1992). Not of toxicological concern at current uses
levels up to 100 mg/l in soft drinks, 41st JECFA (1993)

DEFINITION
The hydrochloride of a natural substance, quinine, obtained from the bark
of various species of Cinchona including Cinchona succirubra, Pavon.
(red cinchona); Cinchona officinalis, Linn; Cinchona calizaya, Wenddell;
Cinchona ledgeriana, Moens.

Chemical names
(8S,9R)-6-methoxy-4-quinolenyl-5-vinyl-2-quinuclidinylmethanol
hydrochloride dihydrate; (8S,9R)-6'-methoxycinchonan-9-ol-hydrochloride
dihydrate

C.A.S. number
6119-47-7

Chemical formula
C20H24N2O2 · HCl · 2H2O

Structural formula


Formula weight
396.92

Assay
Not less than 99.0% and not more than 101.0% on the dried basis

DESCRIPTION
White, silky, glittering needles; odourless, effloresces when exposed to
warm air

FUNCTIONAL USES Flavouring agent

CHARACTERISTICS
IDENTIFICATION


Solubility (Vol. 4)
Soluble in water; very soluble in ethanol; freely soluble in chloroform; very

slightly soluble in ether

Specific rotation (Vol. 4)
[alpha] 25, D: Between -247o and -258o (2% w/v solution in 0.1 N

hydrochloric acid)

Colour test
To 5 ml of a 1 in 1000 solution of the sample add 1 or 2 drops of bromine

TS followed by 1 ml of ammonia TS. The liquid acquires an emerald green
colour.

Test for chloride (Vol. 4)
Passes test

PURITY


Loss on drying (Vol. 4)
Not less than 6% and not more than 10% (105o, 3h)

pH (Vol. 4)
Between 6.0 and 6.8 (1 in 100 solution)

Sulfated ash (Vol. 4)
Not more than 0.1%

Test 2 g of the sample (Method I)

Barium
To 10 ml of a hot solution of the sample (1 in 20) add 1 ml of dilute sulfuric
acid TS. No turbidity is produced.

Sulfates (Vol. 4)
Not more than 0.05%

Test 500 mg of sample as directed in the Limit Test using 0.5 ml of 0.01 N
sulfuric acid in the control

Chloroform-ethanol
1 g of the sample dissolves completely in 7 ml of a mixture of 2 volumes of
insoluble substances
chloroform and 1 volume of absolute ethanol.

Dihydroquinine
Not more than 4% calculated on the basis of the dried substance
hydrochloride
See description under TESTS.

Foreign alkaloids
Dissolve 0.1 g of the sample in 2 ml of concentrated sulfuric acid and add
2 drops of concentrated nitric acid. No change in colour occurs.

Other cinchona alkaloids Dissolve 1 g of the sample in 35 ml of boiling water and add to the boiling
solution 6 ml of a 5% w/v solution of potassium chromate. Allow to cool for
3 h and filter through a sintered glass filter. Add to the clear filtrate 2 drops
of sodium hydroxide TS. No visible change takes place in the solution.
Heat the solution on a water bath for 1 h and then set aside for 24 h. The
solution remains clear.

Lead (Vol. 4)
Not more than 2 mg/kg

Determine using an atomic absorption technique appropriate to the
specified level. The selection of sample size and method of sample
preparation may be based on the principles of the method described in
Volume 4, “Instrumental Methods.”

TESTS



PURITY TESTS


Dihydroquinine
Place about 0.1 g of the sample accurately weighed, in a flask fitted with a
hydrochloride
ground glass stopper. Add 1 ml of 1 N hydrochloric acid. When the sample
has dissolved add 10 ml of methanol and 10 ml of 0.1 N bromine. Close
the flask and keep protected from light for 10 min, shaking gently from
time to time. Rapidly add 20 ml of methanol, 3 ml of N potassium iodide
solution and titrate with 0.1 N sodium thiosulfate using 1 ml of starch TS

added towards the end of the titration as indicator. Carry out a blank
determination. Calculate the content of dihydroquinine hydrochloride, in %
by the formula:


where
n = number of ml of 0.1 N sodium thiosulfate used in the test
n1 = number of ml of 0.1 N sodium thiosulfate used in the blank
p = weight of sample in g

METHOD OF
Dissolve about 150 mg of the sample, accurately weighed, in 20 ml of
ASSAY
acetic anhydride, add 2 drops of malachite green TS and 5.5 ml of
mercuric acetate TS and titrate with 0.1 N perchloric acid from a micro-
buret to a yellow endpoint. Perform a blank determination and correct the
sample titre as necessary. Each ml of 0.1 N perchloric acid is equivalent
to 18.04 mg of C20H24N2O2 · HCl.


Document Outline

  • QUININE HYDROCHLORIDE
    • DEFINITION
      • Chemical names
      • C.A.S. number
      • Chemical formula
      • Structural formula
      • Formula weight
      • Assay
    • DESCRIPTION
    • FUNCTIONAL USES
    • CHARACTERISTICS
      • IDENTIFICATION
        • Colour test
      • PURITY
        • Barium
        • Chloroform-ethanol insoluble substances
        • Dihydroquinine hydrochloride
        • Foreign alkaloids
        • Other cinchona alkaloids
    • TESTS
      • PURITY TESTS
      • Dihydroquinine hydrochloride
    • METHOD OF
    • ASSAY