Oxytetracycline Hydrochloride and Hydrocortisone Ointment
»Oxytetracycline Hydrochloride and Hydrocortisone Ointment contains the equivalent of not less than 90.0percent and not more than 115.0percent of the labeled amount of oxytetracycline (C22H24N2O9),and not less than 90.0percent and not more than 110.0percent of the labeled amount of hydrocortisone.
Packaging and storage— Preserve in collapsible tubes or in well-closed,light-resistant containers.
Minimum fill á755ñ: meets the requirements.
Water,Method Iá921ñ: not more than 1.0%,20mLof a mixture of toluene and methanol (7:3)being used in place of methanol in the titration vessel.
Assay for oxytetracycline— Transfer a suitable,accurately weighed quantity of Ointment to a separator,add 50mLof ether,and shake.Add 20mLof 0.1Nhydrochloric acid,shake,and allow to separate.Collect the acid layer,and repeat the extraction with three additional 20-mLportions of 0.1Nhydrochloric acid.Combine the acid extracts in a 100-mLvolumetric flask,dilute with 0.1Nhydrochloric acid to volume,and mix.Quantitatively dilute a portion of this solution with 0.1Nhydrochloric acid so that the solution so obtained 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 yield a Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.
Assay for hydrocortisone— Proceed with Ointment as directed in the Assay for hydrocortisoneunder Neomycin and Polymyxin B Sulfate,Bacitracin Zinc,and Hydrocortisone Ophthalmic Ointment.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1452
Phone Number:1-301-816-8335
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