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 preparationcorresponds to that in the chromatogram of the Standard preparationobtained as directed in the Assay.

B: Triturate a portion of powdered Tablets,equivalent to about 10mg of trimeprazine,with 10mLof methanol,and centrifuge:5µLof this solution meets the requirements of Identificationtest Cunder Trimeprazine Tartrate.

Medium: 0.01Nhydrochloric acid;500mL.

Apparatus 1: 100rpm.

Time: 45minutes.

Procedure— Determine the amount of C18H22N2Sdissolved by employing UVabsorption at the wavelength of maximum absorbance at about 251nm on filtered portions of the solution under test,suitably diluted with Medium,if necessary,in comparison with a Standard solution having a known concentration of USP Trimeprazine Tartrate RSin the same Medium.

Tolerances— Not less than 75%(Q)of the labeled amount of C18H22N2Sis dissolved in 45minutes.

Procedure for content uniformity— Transfer 1Tablet to a 100-mLvolumetric flask,add about 50mLof 0.1Nhydrochloric acid,and shake by mechanical means until the tablet is completely disintegrated.Add 0.1Nhydrochloric acid to volume,mix,and filter,discarding the first 20mLof the filtrate.Dilute a portion of the subsequent filtrate,quantitatively and stepwise if necessary,with 0.1Nhydrochloric acid to obtain a solution having a known concentration of about 5µg of trimeprazine per mL.Concomitantly determine the absorbances of this solution and a solution of USP Trimeprazine Tartrate RSin the same medium,having a known concentration of about 6µg per mL,in 1-cm cells,at 276nm and at the wavelength of maximum absorbance at about 251nm,with a suitable spectrophotometer,using 0.1Nhydrochloric acid as the blank.Calculate the quantity,in mg,of trimeprazine in the Tablet by the formula: in which Tis the labeled quantity,in mg,of trimeprazine in the Tablet,Dis the concentration,in µg per mL,of trimeprazine in the test solution,based on the labeled quantity per Tablet and the extent of dilution,Cis the concentration,in µg per mL,of USP Trimeprazine Tartrate RSin the Standard solution,0.7991is the factor converting trimeprazine tartrate to trimeprazine,and the parenthetic expressions are the differences in the absorbances of the two solutions at the wavelengths indicated by the subscripts,for the solution from the Tablets (U)and the Standard solution (S),respectively.

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

Assay preparation— Weigh and finely powder not less than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 5mg of trimeprazine,to a 100-mLvolumetric flask,dissolve in and dilute with Mobile phaseto volume,mix,and filter.

Procedure— Separately inject equal volumes (about 25µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C18H22N2Sin the portion of Tablets taken by the formula: in which Cis the concentration,in mg per mL,of USP Trimeprazine Tartrate RSin the Standard preparation,596.89and 746.98are the molecular weights of trimeprazine and trimeprazine tartrate,respectively,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.