Chlortetracycline Hydrochloride Ointment
» Chlortetracycline Hydrochloride Ointment contains not less than 90.0 percent and not more than 125.0 percent of the labeled amount of C22H23ClN2O8·HCl in a suitable ointment base.
Packaging and storage Preserve in collapsible tubes or in well-closed, light-resistant containers.
USP Reference standards 11
Minimum fill 755: meets the requirements.
Water, Method I 921: not more than 0.5%, 20 mL of a mixture of toluene and methanol (7:3) being used in place of methanol in the titration vessel.
Assay Proceed as directed under AntibioticsMicrobial Assays 81, using an accurately weighed quantity of Ointment, equivalent to about 30 mg of chlortetracycline hydrochloride, shaken in a separator with about 50 mL of ether, and extracted with four 20-mL portions of 0.01 N hydrochloric acid. Combine the aqueous extracts in a 100-mL volumetric flask, dilute with 0.01 N hydrochloric acid to volume, and mix. Dilute this stock solution quantitatively and stepwise with water to obtain a Test Dilution having a concentration assumed to be equal to the medium dose level of the Standard.
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USP35NF30 Page 2648