Content area
Full Text
This is a draft proposal for The International Pharmacopoeia (Working document QAS/15.605, January 2015).
The working document with line numbers and tracked changes is available for comment at www.who.int/medicines/areas/qualitv safety/quality assurance/projects/en/. Please address any comments to: World Health Organization, Quality Assurance and Safety: Medicines, Dr Herbert Schmidt, 1211 Geneva 27, Switzerland; fax: +41 22 791 4730; email: [email protected].
[Note from the Secretariat. It is proposed to revise the monograph on Dextromethorphan hydrobromide.]
[Note from the editor. In accordance with WHO editorial policy the text reproduced below does not include tracked changes. Changes from the current monograph are indicated by insert and delete in the working document available at the above-mentioned web address.]
Molecular formula. C^sub 18^H^sub 25^NO,HBr,H^sub 2^O
Relative molecular mass. 370.3
Graphic formula.
Chemical name.
(+)-3-Methoxy-17-methyl-9a,13α-14α-morphinan hydrobromide monohydrate; (+)-c/s1,3,4,9,10,10α-hexahydro-6-methoxy-11-methyl-2/-/-10,4α-iminoethanophenanthrene hydrobromide monohydrate; CAS Reg. No. 6700-34-1 (monohydrate).
Description. A white or almost white, crystalline powder.
Solubility. Sparingly soluble in water; freely soluble in ethanol (~750 g/l) TS; practically insoluble in ether R.
Category. Antitussive.
Storage. Dextromethorphan hydrobromide should be kept in a well-closed container.
Requirements
Definition. Dextromethorphan hydrobromide contains not less than 98.0% and not more than 101.0% of C18H25NO,HBr, calculated with reference to the anhydrous substance.
Identity tests
* Either tests A, F and E or tests B, F, G and E may be applied.
A. Dry a small quantity of the test substance for 4 hours under reduced pressure (not exceeding 0.6 kPa or about 5 mm of mercury) over phosphorus pentoxide R and carry out the examination as described under 1.7 Spectrophotometry in the infrared region.
The infrared absorption spectrum is concordant with the spectrum obtained from dextromethorphan hydrobromide RS similarly prepared or with the reference spectrum of dextromethorphan hydrobromide.
B. The absorption spectrum of a 0.10 mg/ml solution in sodium hydroxide (0.1 mol/l) VS, when observed between 230 nm and 350 nm, exhibits a maximum at 280 nm; the absorbance of a 1 cm layer at this wavelength is about 0.59.
C. [deleted as part of the proposed revision]
D. [deleted as part of the proposed revision]
E. To a 5 mg/ml solution add 0.25 ml of nitric acid (-130 g/l) TS; this test yields reaction B described under 2.1 General identification tests as characteristic of bromides.
F. Determine the specific...