Tetracaine Hydrochloride Injection »Tetracaine Hydrochloride Injection is a sterile solution of Tetracaine Hydrochloride in Water for Injection.It contains not less than 95.0percent and not more than 105.0percent of the labeled amount of C15H24N2O2·HCl. Packaging and storage— Preserve in single-dose or in multiple-dose containers,preferably of Type Iglass,under refrigeration and protected from light.It may be packaged in 100-mLmultiple-dose containers.Injection supplied as a component of spinal anesthesia trays may be stored at room temperature for 12months. Labeling— Label it to indicate that the Injection is not to be used if it contains crystals,or if it is cloudy or discolored. USP Reference standards á11ñ USP Endotoxin RS.USP Tetracaine Hydrochloride RS. Identification— A: It responds to Identificationtest Bunder Tetracaine Hydrochloride. B: The chromatogram of the Assay preparationobtained as directed in the Assayexhibits a major peak for tetracaine,the retention time of which corresponds to that in the chromatogram of the Standard preparationas obtained in the Assay. Bacterial endotoxins á85ñ It contains not more than 0.7USP Endotoxin Unit per mg of tetracaine hydrochloride. pHá791ñ: between 3.2and 6.0. Particulate matter á788ñ: meets the requirements under small-volume injections. Other requirements— It meets the requirements under Injections á1ñ. Assay— Diluent— Prepare a mixture of water and methanol (1:1). Mobile phase— Prepare a suitable mixture of water,acetonitrile,and methanol (60:20:20)containing 0.06%of sulfuric acid,0.5%of sodium sulfate,and 0.02%of sodium 1-heptanesulfonate.The pHis about 2.6.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ). Standard preparation— Dissolve an accurately weighed quantity of USP Tetracaine Hydrochloride RSquantitatively in Diluentto obtain a solution having a known concentration of about 1mg per mL. Resolution solution— Dissolve a quantity of salicylic acid in a portion of the Standard preparationto obtain a solution containing about 4mg of salicylic acid and 1mg of tetracaine hydrochloride per mL. Assay preparation— Transfer an accurately measured volume of Injection equivalent to about 50mg of tetracaine hydrochloride,to a 50-mLvolumetric flask,dilute with Diluentto volume,and mix. Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 305-nm detector and a 3.9-mm ×30-cm column containing packing L1.The flow rate is about 2mLper minute.Chromatograph the Resolution solution,and record the responses as directed for Procedure:the relative retention times are about 0.8for salicylic acid and 1.0for tetracaine;and the resolution,R,between the salicylic acid peak and the tetracaine peak is not less than 2.Chromatograph the Standard preparation,and record the responses as directed for Procedure:the relative standard deviation for replicate injections is not more than 2.0%. Procedure— Separately inject equal volumes (about 5µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the areas for the major peaks.Calculate the quantity,in mg,of tetracaine hydrochloride (C15H24N2O2·HCl)in each mLof the Injection taken by the formula: 50(C/V)(rU/rS), in which Cis the concentration,in mg per mL,of USP Tetracaine Hydrochloride RSin the Standard preparation;Vis the volume,in mL,of Injection taken;and rUand rSare the tetracaine peak responses obtained from the Assay preparationand the Standard preparation,respectively. Auxiliary Information— Staff Liaison:Karen A Russo,Ph.D.,Scientist Expert Committee:(PA1)Pharmaceutical Analysis 1 USP28–NF23Page 1882 Phone Number:1-301-816-8379