Two simple, rapid, and accurate methods for the detn. of bupropion hydrochloride (BUP) in pure and in pharmaceutical prepns. are described. Both methods are based on the measurement of the chloride of its hydrochloride. In the titrimetric method, the chloride content of bupropion hydrochloride is detd. by titrating with mercury(II)nitrate using diphenylcarbazone-bromophenol blue as indicator. Titrimetric method is applicable over a range 2-20 mg of BUP and the reaction stoichiometry is found to be 2:1 (BUP: Hg(NO3)2). The spectrophotometric method involves the addn. of a measured excess of mercury(II) nitrate reagent in formate buffer to the drug, and after ensuring the reaction had gone to completion, the unreacted mercury(II) is treated with a fixed amt. of diphenylcarbazone, and absorbance measured at 515 nm. The absorbance is found to decrease linearly with increasing concn. of BUP and the calibration curve is linear over 1.0-15.0 pg mL-1 BUP. The proposed methods were successfully applied to the detn. of BUP in com. available dosage forms with good accuracy and precision, and without detectable interference by excipients. The accuracy was further ascertained by placebo blank and synthetic mixt. analyses and also by recovery expts. via std.-addn. procedure. [on SciFinder(R)]
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