Change to read:

A: Infrared Absorption á197Kñ.

B: It responds to the tests for Bromide á191ñ.

Delete the following:

Add the following:

Adsorbent: 0.2-mm layer of chromatographic silica gel mixture.

Diluent— Prepare a mixture of methanol and water (9:1).

Test solution— Transfer about 0.2g of Homatropine Hydrobromide to a 5-mLvolumetric flask,dissolve in and dilute with Diluent to volume,and mix.

Standard solution— Dilute 0.5mLof the Test solution with Diluent to 100.0mL.

Tropine reference solution— Prepare a solution of tropine having a concentration of about 0.4mg per mL.

Application volume: 1µL.

Developing solvent system: a mixture of ethyl acetate,anhydrous formic acid,and water (67:16.5:16.5).

Procedure— Proceed as directed for Thin-Layer Chromatographyunder Chromatography á621ñ,applying the Test solution,the Standard solution,and the Tropine reference solution.Spray the plate with Dragendorff's reagent,followed by hydrogen peroxide TS,and immediately cover with a glass plate of the same size.Examine the plate no later than 5to 10minutes after spraying.In the chromatogram obtained from the Test solution,identify the spot corresponding to the principal spot in the chromatogram of the Tropine reference solution:this spot is not more intense than the spot obtained from the Standard solution:not more than 0.5%of tropine is found.USP28

Add the following:

Buffer solution,Mobile phase,System suitability solution,and Chromatographic system— Proceed as directed in the Assay.

Standard solution— Use the Standard preparation,prepared as directed in the Assay.

Test solution— Use the Assay preparation,prepared as directed in the Assay.

Procedure— Separately inject a volume (about 7µL)of the Test solution into the chromatograph,record the chromatogram,and measure the responses for the major peaks.Continue the elution for 2.2times the retention time of the homatropine peak.Disregard the peak for the bromide ion,which appears close to the solvent peak.Calculate the percentage of each impurity in the portion of Homatropine Hydrobromide taken by the formula: in which riand rsare the peak response for each impurity and the sum of all peak responses,respectively,obtained from the Test solution.In addition to not exceeding the limits for each impurity in Table 1,not more than 0.1%of any other individual impurity is found;and not more than 1.0%of total impurities is found. USP28

Change to read:

Buffer solution— Dissolve 6.8g of monobasic potassium phosphate and 7.0g of sodium 1-heptanesulfonate monohydrate in 1000mLof water,adjust with 3Mphosphoric acid to a pHof 2.7,and mix.

Mobile phase— Prepare a filtered and degassed mixture of Buffer solution and methanol (67:33).

Standard preparation— Dissolve an accurately weighed quantity of USP Homatropine Hydrobromide RSin Mobile phase to obtain a solution having a concentration of about 2mg per mL.

System suitability solution— Prepare a solution of USP Scopolamine Hydrobromide RShaving a concentration of about 0.1mg per mL.Transfer 10mLof this solution to a 100-mLvolumetric flask,add 0.5mLof the Standard preparation,and dilute with Mobile phase to volume.

Test preparation— Transfer about 100mg of Homatropine Hydrobromide,accurately weighed,to a 50-mLvolumetric flask,dissolve in and dilute with Mobile phase to volume,and mix.

Chromatographic system (see Chromatography á621ñ)— The liquid chromatograph is equipped with a 210-nm detector and a 4.6-mm ×10-cm column that contains 3-µm packing L1.The flow rate is about 1.5mLper minute.The column temperature is maintained at 40.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the tailing factor is not more than 2.0;and the relative standard deviation for replicate injections is not more than 1.0%.Chromatograph the System suitability solution,and record the peak responses as directed for Procedure:the resolution between homatropine and scopolamine peaks is not less than 1.5.

Procedure— Separately inject equal volumes (about 7µL)of the Standard preparation and the Assay preparation into the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C16H21NO3·HBr in the portion of Homatropine Hydrobromide taken by the formula: in which Cis the concentration,in mg per mL,of USP Homatropine Hydrobromide RSin the Standard preparation;and rUand rSare the peak responses obtained from the Assay preparation and the Standard preparation,respectively.USP28