Promazine Hydrochloride Oral Solution
»Promazine Hydrochloride Oral Solution contains not less than 95.0percent and not more than 110.0percent of the labeled amount of C17H20N2S·HCl.
Packaging and storage— Preserve in tight,light-resistant containers.
USP Reference standards á11ñ— USP Promazine Hydrochloride RS.
NOTE—Throughout the following procedures,protect test or assay specimens,the Reference Standard,and solutions containing them,by conducting the procedures without delay,under subdued light,or using low-actinic glassware.
Identification—
A: Dilute a volume of Oral Solution,equivalent to about 50mg of promazine hydrochloride,with 0.01Nhydrochloric acid to 25mL,and proceed as directed under Identification—Organic Nitrogenous Bases á181ñ,beginning with “Transfer the liquid to a separator”:the Oral Solution meets the requirements of the test.
B: It responds to Identificationtest Bunder Promazine Hydrochloride.
pHá791ñ: between 5.0and 5.5.
Assay— [NOTE—Use low-actinic glassware.]Transfer an accurately measured volume of Oral Solution,or a quantitative dilution of it in water,equivalent to about 10mg of promazine hydrochloride,to a 250-mLseparator.Add water to adjust the volume to about 45mL,add 3mLof sodium hydroxide solution (1in 10),mix,and extract the promazine with five 25-mLportions of ether.Wash the combined ether extracts with 25mLof water,and discard the aqueous washings.Extract the combined ether extract with one 50-mLand four 25-mLportions of 0.1Nhydrochloric acid.Filter the acid extracts through a pledget of cotton washed with 0.1Nhydrochloric acid into a 250-mLvolumetric flask,dilute with the same acid to volume,and mix.Without delay,concomitantly determine the absorbances of this solution and of a Standard solution of USP Promazine Hydrochloride RSin the same medium having a known concentration of about 40µg per mLin 1-cm cells at the wavelength of maximum absorbance at about 301nm,with a suitable spectrophotometer,using 0.1Nhydrochloric acid as the blank.Calculate the quantity,in mg,of C17H20N2S·HCl in each mLof the Oral Solution taken by the formula:
(0.25C/V)(AU/AS),
in which Cis the concentration,in µg per mL,of USP Promazine Hydrochloride RSin the Standard solution,Vis the volume,in mL,of Oral Solution taken,and AUand ASare the absorbances from the assay solution and the Standard solution,respectively.
Auxiliary Information— Staff Liaison:Karen A Russo,Ph.D.,Scientist
Expert Committee:(PA1)Pharmaceutical Analysis 1
USP28–NF23Page 1640
Phone Number:1-301-816-8379