A:Thin-Layer Chromatographic Identification Test á201ñ—

Adsorbent: chromatographic silica gel mixture;0.25mm.

Developing solvent: mixture of butyl alcohol,water,dehydrated alcohol,and glacial acetic acid (6:2:1:1).

Test preparation: Bupivacaine Hydrochloride in Dextrose Injection.

Standard preparations A ,B,and C—Separately prepare (A)a solution of USP Bupivacaine Hydrochloride RSin water,(B)a solution of USP Dextrose RSin water,and (C)a solution of USP Bupivacaine Hydrochloride RSin (B)to obtain solutions having concentrations corresponding to the labeled concentrations of bupivacaine hydrochloride and dextrose in the Injection.

Naphthalenediol reagent— Dissolve 20mg of 1,3-naphthalenediol in 10mLof dehydrated alcohol containing 0.2mLof sulfuric acid.

Iodoplatinate reagent— Mix equal volumes of platinic chloride solution (3in 1000)and potassium iodide solution (6in 100).

Procedure— Separately apply 10µLeach of the Test preparationand Standard preparations Aand Cto a portion of the chromatographic plate,and separately apply 1µLeach of the Test preparationand Standard preparation Bto the remaining portion of the plate.Dry the applications in a current of warm air,develop the chromatograms,remove the plate from the developing chamber,and mark the solvent front.Dry the plate in warm circulating air,and examine the plate under short-wavelength UVlight:the RFvalue of the principal spot obtained from the Test preparationcorresponds to the spots obtained from the adjacent chromatograms of Standard preparations Aand C.Spray the plate with Naphthalenediol reagent,heat at 90for 5minutes,and examine the plate:the RFvalue of the principal blue-purple spot obtained from the Test preparationcorresponds to that obtained in the adjacent chromatogram of Standard preparation B.Cool the plate,spray it with Iodoplatinate reagent,and examine the plate:bupivacaine appears as a blue-purple spot on a salmon-colored background,and the dextrose spots fade slightly:the RFvalue of the bupivacaine spot obtained from the Test preparationcorresponds to those obtained from the adjacent chromatograms of Standard preparations Aand C.

B: It responds to Identificationtest Bunder Bupivacaine Hydrochloride Injection.

pH6.8phosphate buffer ,Mobile phase,Internal standard solution,Standard preparation,Chromatographic system,and Procedure—Proceed as directed in the Assayunder Bupivacaine Hydrochloride Injection.

Assay preparation— Transfer an accurately measured volume of Injection,equivalent to about 50mg of bupivacaine hydrochloride,to a 100-mLvolumetric flask,add 10.0mLof Internal standard solution,dilute with methanol to volume,and mix.