Packaging and storage— Preserve in tight,light-resistant containers,at a temperature not exceeding 30.

Alcohol content,Method Iá611ñ: between 62.0%and 68.0%of C2H5OH.

Assay for total NH3— Transfer 10.0mLto a 250-mLconical flask containing about 50mLof water.Add 30.0mLof 0.5Nsulfuric acid VS,and boil until the solution becomes clear.Cool,add methyl red TS,and titrate the excess acid with 0.5Nsodium hydroxide VS.Perform a blank determination (see Residual Titrationsunder Titrimetry á541ñ).Each mLof 0.5Nsulfuric acid is equivalent to 8.515mg of NH3.

Assay for ammonium carbonate— Transfer 10.0mLto a flask of about 300-mLcapacity.Add 30mLof 0.5Nsodium hydroxide,and boil the mixture,replacing the water lost by evaporation,until the vapors no longer turn moistened red litmus paper blue.Cool,dilute with 100mLof cold,carbon dioxide-free water,add about 6drops of phenolphthalein TS,then add just enough 0.5Nsulfuric acid VSto discharge the color of the phenolphthalein.Add methyl orange TS,and titrate with 0.5Nsulfuric acid VS.Perform a blank determination (see Residual Titrationsunder Titrimetry á541ñ).Each mLof 0.5Nsulfuric acid consumed in the titration with methyl orange TSis equivalent to 48.04mg of (NH4)2CO3.

Expert Committee:(PA1)Pharmaceutical Analysis 1

USP28–NF23Page 137

Phone Number:1-301-816-8379