Bacampicillin Hydrochloride
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4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,6-[(aminophenylacetyl)amino]-3,3-dimethyl-7-oxo-,1-[(ethoxycarbonyl)oxyethyl ester,monohydrochloride,[2S-[2a,5a,6b(S*)]]-.
(2S,5R,6R)-6-[(R)-(2-Amino-2-phenylacetamido)]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid ester with ethyl 1-hydroxyethyl carbonate,monohydrochloride [37661-08-8].
»Bacampicillin Hydrochloride has a potency of not less than 623µg and not more than 727µg of ampicillin (C16H19N3O4S)per mg.
Packaging and storage—
Preserve in tight containers.
Identification—
Prepare a test solution of it in alcohol containing 2mg per mL.Prepare a Standard solution of USP Bacampicillin Hydrochloride RSin alcohol containing 2mg per mL.Apply two 5-µLportions of the test solution 4.0cm apart to a thin-layer chromatographic plate coated with a 0.25-mm layer of chromatographic silica gel mixture (see Chromatography á621ñ).After the spots dry,apply two 5-µLportions of the Standard solution,one midway between the test solution spots and the other to one of the test solution spots.Allow the spots to dry,place the plate in a suitable chromatographic chamber,and develop the chromatogram in a solvent system consisting of a mixture of methylene chloride,chloroform,and alcohol (10:1:1).When the solvent front has moved about three-fourths of the length of the plate,remove the plate from the chamber,and allow to dry.Spray the plate with a spray reagent containing 1g of ninhydrin and 1mLof pyridine in each 100mLof solution in butyl alcohol,and heat at 100
for 10minutes:bacampicillin appears as a purple spot,and the RFvalues of the spots from the test solution and from the combined test solution and Standard solution,respectively,correspond to the RFvalue of the spot obtained from the Standard solution.
for 10minutes:bacampicillin appears as a purple spot,and the RFvalues of the spots from the test solution and from the combined test solution and Standard solution,respectively,correspond to the RFvalue of the spot obtained from the Standard solution.
pHá791ñ:
between 3.0and 4.5,in a solution containing 20mg per mL.
Water,Method Iá921ñ:
not more than 1.0%.
Dimethylaniline á223ñ:
meets the requirement,the Test Preparationbeing prepared using 2Nsodium hydroxide instead of 1Nsodium hydroxide.
Assay—
Mobile phase—
To 500mLof 0.02Mdibasic sodium phosphate add portions of 0.02Mmonobasic sodium phosphate until a pHof 6.8±0.05is reached.Prepare a suitable filtered mixture of this pH6.8buffer and acetonitrile (500:500).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard preparation—
Prepare a solution of USP Bacampicillin Hydrochloride RS,accurately weighed,in water having a known concentration of about 0.8mg per mL,sonicating for about 20minutes to achieve complete dissolution.Pass through a filter of 0.5-µm or finer porosity.
Assay preparation—
Transfer about 80mg of Bacampicillin Hydrochloride,accurately weighed,to a 100-mLvolumetric flask,add 90mLof water,and sonicate for about 20minutes.Dilute with water to volume,mix,and pass through a filter of 0.5-µm or finer porosity.
Chromatographic system
(see Chromatography á621ñ)—The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm ×15-cm column that contains packing L1.The flow rate is about 1mLper minute.Chromatograph the Standard preparation,and record the responses as directed for Procedure:the column efficiency determined from the analyte peak is not less than 3000theoretical plates,and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure—
Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the area responses for the major peaks.Calculate the quantity,in µg,of ampicillin (C16H19N3O4S)equivalent in each mg of the Bacampicillin Hydrochloride taken by the formula:
(349.41/501.99)(100,000C/W)(rU/rS),
in which 349.41and 501.99are the molecular weights of anhydrous ampicillin and bacampicillin hydrochloride,respectively,Cis the concentration,in mg per mL,of USP Bacampicillin Hydrochloride RSin the Standard preparation,Wis the weight,in mg,of the portion of Bacampicillin Hydrochloride taken,and rUand rSare the bacampicillin peak area responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information—
Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 212
Phone Number:1-301-816-8335