Thiethylperazine Maleate
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C22H29N3S2·2C4H4O4 631.76

10H-Phenothiazine,2-(ethylthio)-10-[3-(4-methyl-1-piperazinyl)propyl]-,(Z)-2-butenedioate (1:2).
2-(Ethylthio)-10-[3-(4-methyl-1-piperazinyl)propyl]pheno thiazine maleate (1:2) [1179-69-7].
»Thiethylperazine Maleate contains not less than 98.0percent and not more than 101.5percent of C22H29N3S2·2C4H4O4,calculated on the dried basis.
Packaging and storage— Preserve in tight,light-resistant containers.
USP Reference standardsá11ñ USP Thiethylperazine Maleate 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, Infrared Absorption á197Kñ.
pHá791ñ Dissolve 100mg in 100mLof water,warming,if necessary,to effect solution:the pHof this solution is between 2.8and 3.8.
Loss on drying á731ñ Dry it at 105for 4hours:it loses not more than 0.5%of its weight.
Residue on ignition á281ñ: not more than 0.1%.
Selenium á291ñ The absorbance of the solution from the Test Solution,prepared with 100mg of Thiethylperazine Maleate and 100mg of magnesium oxide,is not greater than one-half that from the Standard Solution(0.003%).
Chromatographic purity— [NOTE—Conduct this test promptly without exposure to daylight and with minimum exposure to artificial light.]
Diluting solution :a mixture of methanol and ammonium hydroxide (49:1).
Test solution— Transfer 100mg of Thiethylperazine Maleate,accurately weighed,to a 5-mLvolumetric flask.Dissolve in and dilute with Diluting solutionto volume,and mix.
Standard solutions— Dissolve an accurately weighed quantity of USP Thiethylperazine Maleate RSin Diluting solution,and dilute quantitatively,and stepwise if necessary,with Diluting solutionto obtain a solution having a known concentration of 20.0mg per mL(Standard solution A).Dilute appropriate portions of this solution quantitatively with Diluting solutionto obtain five Standard solutions Bto Fhaving known concentrations of 0.2,0.1,0.06,0.04,and 0.02mg per mL,respectively.The final concentrations of Standard solutions Bto Frepresent 1%,0.5%,0.3%,0.2%,and 0.1%concentration of Standard solution A,respectively.
Application volume: 5µL.
Developing solvent system: a mixture of ether,cyclohexane,methanol,and ammonium hydroxide (25:10:5:1).
Procedure— Apply equal spots of the Test solutionand Standard solutions Ato Fas directed in Ordinary Impurities á466ñ.Examine the plate under short-and long-wavelength UVlight,then spray the plate with Dragendorff's TS,dry the plate with a stream of nitrogen,and then spray with hydrogen peroxide TS:any secondary spot in the Test solutionis not more than 0.5%,and the sum of all secondary spots is not more than 2.0%.
Organic volatile impurities,Method Vá467ñ: meets the requirements.
Solvent— Use dimethyl sulfoxide.
Assay— Dissolve about 250mg of Thiethylperazine Maleate,accurately weighed,in 30mLof glacial acetic acid,and warm on a steam bath to effect solution.Add 1drop of crystal violet TS,and titrate with 0.1Nperchloric acid VSto a blue-green endpoint.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 31.59mg of C22H29N3S2·2C4H4O4.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 1910
Phone Number:1-301-816-8251