Assay
Proceed as directed for amphotericin B under
AntibioticsMicrobial Assays 81, using an accurately weighed portion of Ointment, equivalent to about 30 mg of amphotericin B, mixed with 10.0 mL of ether in a suitable glass-stoppered conical flask and allowed to stand, with intermittent shaking, for 1 hour. Add 20.0 mL of dimethyl sulfoxide and shake by mechanical means for 10 minutes. Dilute quantitatively and stepwise with dimethyl sulfoxide to a concentration of approximately 20 µg per mL. Quantitatively dilute an accurately measured volume of this stock solution with
Buffer No. 10 to obtain a
Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.