Thiothixene Hydrochloride for Injection »Thiothixene Hydrochloride for Injection is a sterile,dry mixture of Thiothixene Hydrochloride and Mannitol.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of C23H29N3O2S2. Packaging and storage— Preserve in light-resistant Containers for Sterile Solidsas described under Injections á1ñ. USP Reference standards á11ñ USP Endotoxin RS.USP Thiothixene RS. Identification— Constitute a vial of Thiothixene Hydrochloride for Injection with 2.2mLof water.Further dilute one volume of the constituted solution with 4volumes of methanol to obtain a test solution containing 1mg of thiothixene per mL.Apply 10µLof this test solution and 10µLof a Standard solution containing 1mg of USP Thiothixene RSper mLin the same medium to a suitable thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture.Allow the spots to dry,and develop the chromatogram in a solvent system consisting of a mixture of isopropyl alcohol and diethylamine (25:1)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the developing chamber,mark the solvent front,air-dry for 30minutes,and then oven-dry at 110for 30minutes.Locate the spots on the plate by viewing under short-wavelength UVlight.Spray the plate with alkaline permanganate spray reagent (prepared by dissolving 0.5g of potassium permanganate and 2.0g of sodium carbonate in 100mLof water):the RFvalue of the principal spot obtained from the test solution,under both detection conditions,corresponds to that obtained from the Standard solution. Bacterial endotoxins á85ñ It contains not more than 88.0USP Endotoxin Units per mg of thiothixene. pHá791ñ: between 2.3and 3.7,in the solution constituted as directed in the labeling. Water,Method Iá921ñ: not more than 4.0%. Other requirements— It meets the requirements under Injections á1ñ. Assay— [NOTE—Perform the dilution operations in low-actinic glassware.] Mobile phase ,Standard preparation,and Chromatographic system—Prepare as directed in the Assayunder Thiothixene. Assay preparation— Constitute a vial of Thiothixene Hydrochloride for Injection with an accurately measured volume (VLmL)of water as directed in the labeling.Transfer an accurately measured volume (VFmL)of the constituted solution,equivalent to about 5mg of thiothixene,to a 250-mLvolumetric flask,dilute with methanol to volume,and mix. Procedure— Proceed as directed for Procedurein the Assayunder Thiothixene.Calculate the quantity,in mg,of C23H29N3O2S2in each mLof the constituted solution taken by the formula: (250CVL/VF)(rU/rS), in which Cis the concentration,in mg per mL,of USP Thiothixene RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively. Auxiliary Information— Staff Liaison:Ravi Ravichandran,Ph.D.,Senior Scientist Expert Committee:(PA3)Pharmaceutical Analysis 3 USP28–NF23Page 1921 Phone Number:1-301-816-8330