Codeine Phosphate
(koe' deen fos' fate).
C18H21NO3·H3PO4·½H2O
406.37
406.37Morphinan-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].» Codeine Phosphate contains not less than 99.0 percent and not more than 101.5 percent of C18H21NO3·H3PO4, calculated on the anhydrous basis.
Packaging and storage—
Preserve in tight, light-resistant containers. Store up to 40
as permitted by the manufacturer.
as permitted by the manufacturer.
USP Reference standards 
11
—
11—
USP Codeine Phosphate RS 
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Identification—
B:
Neutralize a solution (1 in 50) with 6 N ammonium hydroxide, and add silver nitrate TS: a yellow precipitate of silver phosphate is formed, and it is soluble in 2 N nitric acid and in 6 N ammonium hydroxide.
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%.
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.
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.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Clydewyn M. Anthony, Ph.D.
Senior Scientific Liaison 1-301-816-8139 |
(SM22010) Monographs - Small Molecules 2 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 2758
Pharmacopeial Forum: Volume No. 30(5) Page 1597