Packaging and storage—
Preserve in single-dose or in multiple-dose containers, preferably of Type I glass. It may be packaged in 50-mL multiple-dose containers.
Identification—
Evaporate about 5 mL of the chloroform solution of the fatty acids obtained in the test for
Iodine value of the fatty acids on a steam bath nearly to dryness, dissolve the residue in 1 mL of chloroform, and add 1 drop of sulfuric acid: a transient red color is produced, and it changes to brown-red.
Acidity and alkalinity—
To 5 mL of Injection add 5 mL of alcohol and 2 drops of
phenolphthalein TS. If no red color is produced, not more than 0.50 mL of 0.10 N sodium hydroxide is required to impart a distinct red color. If a red color is produced, not more than 0.30 mL of 0.10 N acid is required to discharge it. For concentrations of morrhuate sodium other than 5%, no larger than proportional volumes of alkali and acid are required.
Iodine value of the fatty acids—
Transfer to a tared, 125-mL conical flask the solvent hexane solution of the fatty acids obtained in the
Assay. Evaporate at about 60
to dryness, dry the residue in vacuum over silica gel for 18 hours, and weigh. Dissolve the residue in chloroform to make 100.0 mL of solution, and determine the iodine value (see
Fats and Fixed Oils 
401
) on a 25.0-mL aliquot of the solution: the iodine value is not less than 130.
Other requirements—
It meets the requirements under
Injections 1, except that at times it may show a slight turbidity or precipitate.
Assay—
Transfer an accurately measured volume of Injection, equivalent to about 500 mg of morrhuate sodium, to a small separator containing 30.0 mL of 0.1 N sulfuric acid VS, add 25 mL of solvent hexane, shake gently, and allow to separate. Withdraw the aqueous layer into a beaker or flask, and wash the solvent hexane layer with two 10-mL portions of water, adding the washings to the main aqueous solution. Retain the hexane solution for the test for
Iodine value of the fatty acids. Add
methyl orange TS, and titrate the excess acid in the aqueous solution with 0.1 N sodium hydroxide VS. Each mL of 0.1 N sulfuric acid is equivalent to 32.4 mg of morrhuate sodium.
