Assay
Dissolve about 0.1 g of Mitotane, accurately weighed, in methanol, and dilute quantitatively and stepwise with methanol to obtain a solution having a concentration of about 200 µg per mL. Similarly prepare a solution in methanol of
USP Mitotane RS, diluted quantitatively and stepwise with methanol to yield a Standard solution having a known concentration of about 200 µg per mL. Concomitantly determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 268 nm, with a suitable spectrophotometer, using methanol as the blank. Calculate the quantity, in mg, of C
14H
10Cl
4 in the portion of Mitotane taken by the formula:
0.5C(AU / AS),
in which
C is the concentration, in µg per mL, of
USP Mitotane RS in the Standard solution, and
AU and
AS are the absorbances of the solution of Mitotane and the Standard solution, respectively.