Dextromoramide Tablets

General Notices

Action and use

Opioid receptor agonist; analgesic.

Definition

Dextromoramide Tablets contain Dextromoramide Tartrate.

The tablets comply with the requirements stated under Tablets and with the following requirements.

Content of dextromoramide, C25H32N2O2

90.0 to 110.0% of the stated amount.

Identification

A. Shake a quantity of the powdered tablets containing the equivalent of 30 mg of dextromoramide with 10 mL of water and filter. Make the filtrate alkaline with 5m ammonia and extract with two 5 mL quantities of ether. Dry the combined ether extracts over anhydrous sodium sulfate, filter and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of dextromoramide (RS 090).
B. Shake a quantity of the powdered tablets containing the equivalent of 25 mg of dextromoramide with 25 mL of 1m hydrochloric acid and filter. The light absorption of the resulting solution, Appendix II B, in the range 230 to 350 nm exhibits maxima at 254, 259 and 264 nm.

TEST

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.

(1) Shake a quantity of the powdered tablets containing the equivalent of 20 mg of dextromoramide with 1 mL of methanol for 5 minutes, centrifuge and use the supernatant liquid.
(2) Dilute 1 volume of solution (1) to 100 volumes with methanol.
chromatographic conditions
(a) Use as the coating silica gel G.
(b) Use the mobile phase as described below.
(c) Apply 10 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in air, spray with dilute potassium iodobismuthate solution.
mobile phase

methanol

limits

Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2).

Assay

Weigh and powder 20 tablets. Shake a quantity of the powder containing the equivalent of 0.1 g of dextromoramide with 25 mL of 1m hydrochloric acid for 5 minutes. Add 25 mL of water, make alkaline with 5m sodium hydroxide and extract with four 25 mL quantities of chloroform. Wash the combined chloroform extracts with two 10-mL quantities of water and extract the combined washings with 10 mL of chloroform. Filter the combined chloroform extracts through absorbent cotton moistened with chloroform and wash the filter with a small quantity of chloroform. Heat on a water bath until the volume is reduced to about 25 mL, cool, add 50 mL of anhydrous acetic acid, previously neutralised to crystal violet solution, and titrate with 0.02m perchloric acid VS using crystal violet solution as indicator. Each mL of 0.02m perchloric acid VS is equivalent to 7.851 mg of C25H32N2O2.

Labelling

The quantity of active ingredient is stated in terms of the equivalent amount of dextromoramide.