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: Transfer a volume of it,equivalent to about 20mg of chlorpromazine hydrochloride,to a 125-mLseparator.Add 10mLof water,2mLof sodium hydroxide solution (1in 2),and mix.Extract with three 30-mLportions of ether.Filter the combined ether extracts through anhydrous sodium sulfate.With the aid of a stream of nitrogen evaporate the ether to about 5mL.Quantitatively transfer the solution to a 40-mLcentrifuge tube.Evaporate with a stream of nitrogen and mild heat to dryness.Dissolve the residue in 100mLof methanol to obtain the Test solution.Separately apply 15µLof this Test solution and 15µLof a Standard solution,containing 0.2mg of USP Chlorpromazine Hydrochloride RSper mLof methanol,to a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel.Develop the chromatogram in a chamber containing a freshly prepared mixture of ethyl acetate that has been saturated with ammonium hydroxide,ether,and methanol (75:25:20)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chamber,air-dry,and spray with Iodoplatinate reagent prepared by dissolving 100mg of platinic chloride in 10mLof 0.1Nhydrochloric acid,adding 25mLof potassium iodide solution (1in 25),0.5mLof formic acid,and diluting with water to 100mL:the RFvalue of the principal spot from the test solution corresponds to that obtained from the Standard solution.

B: Dilute a portion of the Syrup with an equal volume of water:the resulting solution responds to the tests for Chloride á191ñ.

Chlorpromazine sulfoxide standard solution— Transfer 5mLof a solution in dilute hydrochloric acid (1in 100)of USP Chlorpromazine Hydrochloride RScontaining 10.6mg per mLto a 50-mLvolumetric flask.Add 2mLof 30%hydrogen peroxide and heat at 60for 10minutes.Cool,dilute with 1Msodium bisulfite to volume,and mix.Transfer 10.0mLto a 60-mLseparator,add 2mLof sodium hydroxide solution (1in 2),and mix.Extract with three 30-mLportions of ether.Filter the extracts through ether-wetted anhydrous sodium sulfate into a 250-mLconical flask.Cautiously evaporate the extracts to dryness.Dissolve the residue in 10.0mLof methanol,and filter if necessary.Each mLof this solution contains 1mg of chlorpromazine sulfoxide.

Procedure— Transfer an accurately measured volume of the Syrup,equivalent to about 20mg of chlorpromazine hydrochloride,to a 125-mLseparator.Add 10mLof water and 2mLof sodium hydroxide solution (1in 2),and mix.Extract with three 30-mLportions of ether.Filter the combined ether extracts through anhydrous sodium sulfate.With the aid of a stream of nitrogen evaporate the ether to about 5mL.Quantitatively transfer the solution to a 40-mLcentrifuge tube.Evaporate with a stream of nitrogen and mild heat to dryness.Dissolve the residue in 1.0mLof methanol to obtain the Test solution.Separately apply 15µLof this Test solution and 15µLof a Chlorpromazine sulfoxide standard solutionto a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel.Develop the chromatogram in a chamber containing a freshly prepared mixture of ethyl acetate that has been saturated with ammonium hydroxide,ether,and methanol (75:25:20)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chamber,air-dry,and spray with Iodoplatinate reagent prepared by dissolving 100mg of platinic chloride in 10mLof 0.1Nhydrochloric acid,adding 25mLof potassium iodide solution (1in 25)and 0.5mLof formic acid,and diluting with water to 100mL.The chromatogram from the Test solution may exhibit a secondary spot whose RFvalue corresponds to,and whose size and intensity are not greater than,those of the spot from the Chlorpromazine sulfoxide standard solution(5.0%).

1.25C(A254-A277)U/V(A254-A277)S,