Promazine Hydrochloride Oral Solution
» Promazine Hydrochloride Oral Solution contains not less than 95.0 percent and not more than 110.0 percent of the labeled amount of C17H20N2S·HCl.
Packaging and storage— Preserve in tight, light-resistant containers.
USP Reference standards 11
USP Promazine Hydrochloride RS Click to View Structure
[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 50 mg of promazine hydrochloride, with 0.01 N hydrochloric acid to 25 mL, and proceed as directed under Identification—Organic Nitrogenous Bases 181, beginning with “Transfer the liquid to a separator”: the Oral Solution meets the requirements of the test.
B: It responds to Identification test B under Promazine Hydrochloride.
pH 791: between 5.0 and 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 10 mg of promazine hydrochloride, to a 250-mL separator. Add water to adjust the volume to about 45 mL, add 3 mL of sodium hydroxide solution (1 in 10), mix, and extract the promazine with five 25-mL portions of ether. Wash the combined ether extracts with 25 mL of water, and discard the aqueous washings. Extract the combined ether extract with one 50-mL and four 25-mL portions of 0.1 N hydrochloric acid. Filter the acid extracts through a pledget of cotton washed with 0.1 N hydrochloric acid into a 250-mL volumetric 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 RS in the same medium having a known concentration of about 40 µg per mL in 1-cm cells at the wavelength of maximum absorbance at about 301 nm, with a suitable spectrophotometer, using 0.1 N hydrochloric acid as the blank. Calculate the quantity, in mg, of C17H20N2S·HCl in each mL of the Oral Solution taken by the formula:
(0.25C / V)(AU / AS)
in which C is the concentration, in µg per mL, of USP Promazine Hydrochloride RS in the Standard solution, V is the volume, in mL, of Oral Solution taken, and AU and AS are the absorbances from the assay solution and the Standard solution, respectively.
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Topic/Question Contact Expert Committee
Monograph Mary S. Waddell
Scientific Liaison
1-301-816-8124
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
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USP35–NF30 Page 4439