C18H21NO3·H3PO4·½H2O 406.37

Morphinan-6-ol, 7,8-didehydro-4,5-epoxy-3-methoxy-17-methyl-, (5,6)-, phosphate (1:1) (salt), hemihydrate.
7,8-Didehydro-4,5-epoxy-3-methoxy-17-methylmorphinan-6-ol phosphate (1:1) (salt) hemihydrate [41444-62-6].

Anhydrous 397.37 [52-28-8].

Packaging and storage— Preserve in tight, light-resistant containers. Store up to 40 as permitted by the manufacturer.

USP Reference standards 11— USP Codeine Phosphate RS.

Identification—

Acidity— Dissolve 100 mg in 20 mL of water, and titrate with 0.010 N sodium hydroxide to a pH of 5.4, using a pH meter: not more than 1.0 mL of 0.010 N sodium hydroxide is required.

Water, Method I 921: not more than 3.0%.

Chloride— To 10 mL of a solution (1 in 100), acidified with nitric acid, add a few drops of silver nitrate TS: no opalescence is produced immediately.

Sulfate— To 10 mL of a solution (1 in 100) add a few drops of barium chloride TS: no turbidity is produced immediately.

Limit of morphine— Dissolve about 50 mg of potassium ferricyanide in 10 mL of water, and add 1 drop of ferric chloride TS and 1 mL of a solution of Codeine Phosphate (1 in 100): no blue color is produced immediately.

Chromatographic purity— Using Codeine Phosphate, proceed as directed in the test for Chromatographic purity under Codeine, except to use a mixture of 0.01 N hydrochloric acid and dehydrated alcohol (4:1), instead of dehydrated alcohol, to prepare Solution A, Solution B, and Solution C.

Residual solvents 467: meets the requirements.

Assay— Dissolve about 1 g of Codeine Phosphate, accurately weighed, in 50 mL of glacial acetic acid, warming slightly if necessary to effect solution, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 39.74 mg of C18H21NO3·H3PO4.

Expert Committee : (MDCCA05) Monograph Development-Cough Cold and Analgesics

USP29–NF24 Page 583

Phone Number : 1-301-816-8139