Bromodiphenhydramine Hydrochloride Oral Solution
» Bromodiphenhydramine Hydrochloride Oral Solution contains not less than 93.0 percent and not more than 107.0 percent of the labeled amount of bromodiphenhydramine hydrochloride (C17H20BrNO·HCl).
Packaging and storage— Preserve in tight, light-resistant containers.
Identification, Infrared Absorption 197K
Test specimen— Transfer the final solution obtained from the titration in the Assay to a separator, add about 1 mL of 0.1 N sulfuric acid, and shake with 25 mL of ether. (Methyl red enters the ether phase.) Drain the aqueous layer into another separator, add 5 mL of 1 N sodium hydroxide, and shake with 10 mL of chloroform. Drain the chloroform layer into a small flask containing 2 g of anhydrous sodium sulfate, and swirl. Pour the chloroform solution through a small cotton pledget, pre-rinsed with chloroform, into a beaker, and evaporate to about 5 mL. Apply a few drops of the solution directly to a potassium bromide plate, and completely remove the chloroform by warming for 2 to 3 minutes under an IR lamp.
Alcohol content, Method I 611: between 12.0% and 15.0% of C2H5OH.
Assay— Evaporate an accurately measured volume of Oral Solution, equivalent to about 250 mg of bromodiphenhydramine hydrochloride, to about half the original volume, using a suitable vacuum evaporator. Transfer the concentrated solution to a 250-mL separator, with the aid of sufficient warm water to bring the volume to the original volume. Add 20 g of sodium chloride, and shake until dissolved. Add 5 mL of 1 N sodium hydroxide, shake with 100 mL of ether, and drain the aqueous layer into a second separator containing 50 mL of ether. Shake, and discard the aqueous layer. Wash the ether solutions with two 20-mL portions of water, shaking each aqueous portion successively in the two separators, and then discard the aqueous solutions. Extract the ether solutions successively with 10.0 mL of 0.1 N sulfuric acid VS, followed by two 5-mL portions of water, and collect the aqueous extracts in a conical flask. Add methyl red TS to the solution in the flask, and titrate the excess acid with 0.02 N sodium hydroxide VS. Perform a blank determination (see Residual Titrations under Titrimetry 541). Each mL of 0.1 N sulfuric acid is equivalent to 37.07 mg of bromodiphenhydramine hydrochloride (C17H20BrNO·HCl).
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