Oxytetracycline Hydrochloride and Polymyxin B Sulfate Vaginal Inserts
(Monograph under this new title—to become official October 1,2005)
(Current monograph title is Oxytetracycline Hydrochloride and Polymyxin B Sulfate Vaginal Tablets)
»Oxytetracycline Hydrochloride and Polymyxin B Sulfate Vaginal Inserts contain the equivalent of not less than 90.0percent and not more than 120.0percent of the labeled amounts of oxytetracycline (C22H24N2O9)and polymyxin B.
Packaging and storage— Preserve in well-closed containers.
Loss on drying á731ñ— Dry about 100mg,accurately weighed,of powdered Vaginal Inserts in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60for 3hours:it loses not more than 3.0%of its weight.
Assay for oxytetracycline— Place not fewer than 5Vaginal Inserts in a high-speed blender jar containing an accurately measured volume of 0.1Nhydrochloric acid,so that the stock solution obtained after blending for 3to 5minutes contains not less than 150µg of oxytetracycline per mL.Proceed as directed for oxytetracycline under Antibiotics—Microbial Assays á81ñ,using an accurately measured volume of this solution diluted quantitatively and stepwise with water to obtain a Test Dilutionhaving a concentration of oxytetracycline assumed to be equal to the median dose level of the Standard.
Assay for polymyxin B— Weigh and finely powder not fewer than 5Vaginal Inserts.Transfer an accurately weighed portion of the powder,equivalent to about 100,000USP Polymyxin B Units,to a filter funnel equipped with a solvent-resistant membrane filter (1-µm or finer porosity).Wash the powder with five 20-mLportions of acetone,applying vacuum,and discarding the accumulated filtrate.[NOTE—If necessary,wash the powder with additional portions of acetone to remove any yellow color.]Carefully transfer the filter and the washed powder to a beaker containing about 400mLof Buffer No.6(see Antibiotics—Microbial Assays á81ñ),and stir.Transfer the contents of the beaker to a 500-mLvolumetric flask with the aid of Buffer No.6,dilute with the same solvent to volume,and mix.Proceed as directed for polymyxin Bunder Antibiotics—Microbial Assays á81ñ,using an accurately measured volume of this solution diluted quantitatively and stepwise with Buffer No.6to yield a Test Dilutionhaving a concentration of polymyxin Bassumed to be equal to the median dose level of the Standard.
(Official October 1,2005)
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1454
Pharmacopeial Forum:Volume No.29(3)Page 646
Phone Number:1-301-816-8335