Thiothixene Hydrochloride Oral Solution »Thiothixene Hydrochloride Oral Solution contains an amount of thiothixene hydrochloride equivalent to not less than 90.0percent and not more than 110.0percent of the labeled amount of thiothixene (C23H29N3O2S2). Packaging and storage— Preserve in tight,light-resistant containers. USP Reference standards á11ñ USP Thiothixene RS. Identification— Transfer a portion of Oral Solution,equivalent to about 20mg of thiothixene hydrochloride,to a separator containing 20.0mLof chloroform.Render the aqueous layer just basic with ammonium hydroxide,shake for 1minute,and allow the layers to separate.Pass a portion of the chloroform layer through filter paper,previously washed with chloroform;and use the clear filtrate for the test.Proceed as directed in the Identificationtest under Thiothixene Capsules,beginning with “Apply 10µLof this test solution.” Uniformity of dosage units á905ñ FOR ORAL SOLUTION PACKAGED IN SINGLE-UNIT CONTAINERS: meets the requirements. Deliverable volume á698ñ FOR ORAL SOLUTION PACKAGED IN MULTIPLE-UNIT CONTAINERS: meets the requirements. pHá791ñ: between 2.0and 3.0. Alcohol content,Method IIá611ñ: if present,between 90.0%and 110.0%of the labeled amount,the labeled amount being not more than 7.0%of C2H5OH,determined by the gas-liquid chromatographic procedure,acetonitrile being used as the internal standard. 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— Transfer an accurately measured volume of Oral Solution,equivalent to about 25mg of thiothixene,to a 25-mLvolumetric flask;dissolve in and dilute with methanol to volume;and mix.Pipet 2mLof this solution into a 100-mLvolumetric flask,dilute with methanol to volume,and mix. Procedure— Proceed as directed for Procedurein the Assayunder Thiothixene.Calculate the quantity,in mg,of thiothixene (C23H29N3O2S2)in each mLof the Oral Solution taken by the formula: (1250C/V)(rU/rS), in which Cis the concentration,in mg per mL,of USP Thiothixene RSin the Standard preparation;Vis the volume,in mL,of Oral Solution taken;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 1922 Pharmacopeial Forum:Volume No.29(6)Page 1993 Phone Number:1-301-816-8330