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.

A: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

B: Mix 10 mL of Oral Solution with about 30 mL of water in a separator, render the solution alkaline with 1 N sodium hydroxide, and extract with two 30-mL portions of ether. Transfer the ether extracts to a beaker, evaporate the ether by warming, and dissolve the residue in 5 mL of methanol: 5 µL of this solution meets the requirements of Identification test C under Trimeprazine Tartrate.

Mobile phase and Chromatographic system —Proceed as directed in the Assay.

Standard solution— Transfer about 60.6 mg of USP Trimeprazine Tartrate RS, accurately weighed, to a 50-mL volumetric flask. Add 5 mL of dilute hydrochloric acid (1 in 100) followed by 2 mL of 30 percent hydrogen peroxide, and heat at 60 for 10 minutes. Cool, dilute with 1 M sodium bisulfite to volume, and mix. Transfer 10.0 mL to a 60-mL separator, add 2 mL of sodium hydroxide solution (1 in 2), and mix. Extract with three 30-mL portions of ether. Filter the extracts through ether-wetted anhydrous sodium sulfate into a 250-mL conical flask. Cautiously evaporate the flask to dryness. Dissolve the residue in 10.0 mL of methanol, and filter if necessary. Each mL of this solution contains about 1 mg of trimeprazine sulfoxide. Transfer 1.0 mL of this solution to a 500-mL volumetric flask, dilute with Mobile phase to volume, and mix to obtain a solution containing about 0.0024 mg per mL of trimeprazine sulfoxide, expressed as trimeprazine tartrate.

Test solution— Use the Assay preparation as directed in the Assay.

Procedure— Separately inject equal volumes (about 25 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the peaks. The Test solution may exhibit a minor peak whose retention time corresponds to the peak exhibited by the Standard solution and whose retention time is about 0.6 relative to the main peak. Calculate the concentration, in mg per mL, of trimeprazine sulfoxide, in the portion of Oral Solution taken by the formula: in which C is the concentration, in mg per mL, of trimeprazine tartrate in the Standard solution; V is the volume, in mL, of Oral Solution taken; 596.89 and 746.98 are the molecular weights of trimeprazine and trimeprazine tartrate, respectively, and rU and rS are the peak responses obtained from the Test solution and the Standard solution, respectively. Not more than 0.036 mg per mL is found.

(Official January 1, 2007)

Mobile phase, Standard preparation, and Chromatographic system— Proceed as directed in the Assay under Trimeprazine Tartrate.

Assay preparation— Using a “to contain” pipet, transfer an accurately measured volume of Oral Solution, equivalent to about 2.5 mg of trimeprazine, to a 100-mL volumetric flask containing 50 mL of Mobile phase. Rinse the pipet with Mobile phase, collecting the rinses in the volumetric flask. Dilute with Mobile phase to volume, and mix.

Procedure— Separately inject equal volumes (about 25 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of trimeprazine (C18H22N2S) in each mL of Oral Solution taken by the formula: in which C is the concentration, in mg per mL, of USP Trimeprazine Tartrate RS in the Standard preparation; V is the volume, in mL, of Oral Solution taken; 596.89 and 746.98 are the molecular weights of trimeprazine and trimeprazine tartrate, respectively; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.