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This is a draft proposal for The International Pharmacopoeia (Working document QAS/15.614, May 2015).
The working document with line numbers is available for comment at
www.who.int/medicines/areas/quality_safety/quality_assurance/projects/en/.
Please address any comments to: World Health Organization, Quality Assurance and Safety: Medicines, Dr Herbert Schmidt, CH-1211 Geneva 27, Switzerland; fax: +41 22 791 4730; email: [email protected].
[Note from the Secretariat. It is proposed to revise the monograph on Levonorgestrel. Comments are particularly sought on whether the monograph should include a limit test for dextronorgestrel.]
[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",H"00"
Relative molecular mass. 312.5
Graphic formula
Chemical name. (-)-13-Ethyl-17-hydroxy-18,19-dinor-17a-pregn-4-en-20-yn-3-one; CAS Reg. No. 797-63-7.
Description. A white or almost white, crystalline powder.
Solubility. Practically insoluble in water; sparingly soluble in dichloromethane R, slightly soluble in ethanol (-750 g/L) TS and ether R.
Category. Contraceptive.
Storage. Levonorgestrel should be kept in a well-closed container, protected from light.
Requirements
Definition. Levonorgestrel contains not less than 98.0% and not more than 102.0% of C2iH2802, calculated with reference to the dried substance.
Identity tests
* Either tests A and C or tests B and C may be applied.
A. 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 levonorgestrel RS or with the reference spectrum of levonorgestrel.
B. Carry out the examination as described under 1.14.4 High-performance liquid chromatography using the conditions described under "Related substances", Method A. Prepare the following solutions. For solution (1 ) dissolve 10 mg of the test substance in 7 mL of acetonitrile R using sonication and dilute to 10 mL with water R. Dilute 1 volume to 100 volumes with a solvent mixture consisting of 30 volumes of water R and 70 volumes of acetonitrile R. For solution (2) use a solution containing 0.01 mg levonorgestrel RS per mL of the same solvent mixture. Inject 50 pL of solution (1 ) and (2). The retention time of the principal peak in the chromatogram obtained from solution (1) is similar to the principal peak in the...