Procedure for content uniformity
Place 1 Tablet in a 500-mL volumetric flask containing 100 mL of 0.1 N hydrochloric acid, and shake for 15 minutes. Dilute with 0.1 N hydrochloric acid to volume, mix, and filter, discarding the first 20 mL of filtrate. Dilute a portion of the subsequent filtrate quantitatively and stepwise, if necessary, with 0.1 N hydrochloric acid to provide a solution containing approximately 12 µg of apomorphine hydrochloride per mL. Concomitantly determine the absorbances of this solution and of a solution of
USP Apomorphine Hydrochloride RS in the same medium having a known concentration of about 12 µg of anhydrous apomorphine hydrochloride per mL, in 1-cm cells at the wavelength of maximum absorbance at about 273 nm, with a suitable spectrophotometer, using 0.1 N hydrochloric acid as the blank. Calculate the quantity, in mg, of C
17H
17NO
2·HCl·½H
2O in the Tablet taken by the formula:
(312.80 / 303.79)(TC / D)(AU / AS),
in which 312.80 and 303.79 are the molecular weights of apomorphine hydrochloride hemihydrate and anhydrous apomorphine hydrochloride, respectively;
T is the labeled quantity, in mg, of apomorphine hydrochloride in the Tablet;
C is the concentration, in µg per mL, of anhydrous apomorphine hydrochloride in the Standard solution;
D is the concentration, in µg per mL, of apomorphine hydrochloride in the solution from the Tablet, based upon the labeled quantity per Tablet and the extent of dilution; and
AU and
AS are the absorbances of the solution from the Tablet and the Standard solution, respectively.