Aminobenzoic Acid Topical Solution
»Aminobenzoic Acid Topical Solution contains,in each mL,not less than 45mg and not more than 55mg of aminobenzoic acid (C7H7NO2).
Packaging and storage—
Preserve in tight,light-resistant containers.
Identification—
A:
To 1mLof Topical Solution add 1mLof 1Nsodium hydroxide,and add,in the order named,0.5mLof potassium iodide TS,0.5mLof 3Nhydrochloric acid,and 0.5mLof sodium hypochlorite TS:a brown precipitate is formed.
B:
To 1mLof Topical Solution add 2mLof 3Nhydrochloric acid,and cool to about 10
.Add 1mLof sodium nitrite solution (1in 100),then add a solution prepared by mixing 50mg of 2-naphthol with 3mLof sodium hydroxide solution (1in 10):a red color is produced.
.Add 1mLof sodium nitrite solution (1in 100),then add a solution prepared by mixing 50mg of 2-naphthol with 3mLof sodium hydroxide solution (1in 10):a red color is produced.
Specific gravity á841ñ:
not less than 0.895and not more than 0.905.
Assay—
Transfer 5mLof Topical Solution,accurately measured,to a suitable open vessel,evaporate on a steam bath to dryness,and proceed as directed under Nitrite Titration á451ñ,beginning with “Add 20mLof hydrochloric acid.”Each mLof 0.1Msodium nitrite is equivalent to 13.71mg of C7H7NO2.
Auxiliary Information—
Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28–NF23Page 123
Phone Number:1-301-816-8389