Indexed on: 25 Jan '17Published on: 25 Jan '17Published in: Journal of AOAC International
Accurate and precise TLC-densitometric and HPLC-diode-array detector (DAD) methods have been developed and validated toresolve two binary mixtures containing pyridoxine hydrochloride (PYH) with either cyclizine hydrochloride (CYH) or meclizine hydrochloride (MEH). In the developed TLC-densitometric method, chromatographic separation of the three studied drugs was carried out on silica gel 60 F<sub>254</sub> plates using a developing system containing methylene chloride + acetone + methanol (7 + 1 + 0.5, v/v/v) scanning separated bands at 220 nm. Beer-Lambert law was obeyed in the ranges of 0.2-5, 0.2-4, and 0.2-4 μg/band for PYH, CYH, and MEH, respectively. On the other hand, the developed HPLC-DAD method depended on chromatographic separation on a Zorbax Eclipse C<sub>18</sub> column using methanol-KH<sub>2</sub>PO<sub>4</sub> (0.05 M; 90 + 10, v/v; pH 5, with H<sub>3</sub>PO<sub>4</sub> and KOH) as the mobile phase, a flow rate of 1 mL/min, and UV scanning at 220 nm. A linear relationship was obtained between the integrated peak area and the concentration in the ranges of 10-50, 10-50, and 7-50 μg/mL for PYH, CYH, and MEH, respectively. The proposed methods were successfully applied for the determination of the cited drugs in their pharmaceutical formulations. Statistical comparison with the reported methods using Student's <em>t</em>- and <em>F</em>-tests found there were no significant differences between the proposed and reported methods for accuracy and precision.