Abstract
Abstract
Four new methods were developed and validated for the determination of cinnarizine HCl in its binary mixture with piracetam in pure and pharmaceutical preparations. The first one was a densitometric analysis that provides a simple and rapid method for the separation and quantification of cinnarizine HCl. The method depends on the quantitative densitometric evaluation of thin-layer chromatograms of cinnarizine HCl at 252 nm over concentration range of 1–6 μg/spot, with a mean accuracy of 100.05 ± 0.91%. The second method was determination of the drug using a colorimetric method that utilizes the reaction of 3-methylbenzothiazolin-2-one in the presence of FeCl3 as an oxidant. The green color of the resulting product was measured at 630 nm over concentration range 10–40 μg/mL, with a mean accuracy of 100.10 ± 1.13%. The third method was a direct spectrophotometric determination of cinnarizine HCl at 252 nm over the concentration range 7–20 μg/mL, while piracetam was determined by derivative ratio spectrophotometry at 221.6 nm over concentration range 5–30 μg/mL, with a mean accuracy of 100.14 ± 0.79 and 100.26 ± 1.24% for cinnarizine HCl and piracetam, respectively. The last method was a liquid chromatography analysis of both cinnarizine HCl and piracetam, depending on quantitative evaluation of chromatograms of cinnarizine HCl and piracetam at 252 and 212 nm, respectively, over the concentration range 10–200 μg/mL for cinnarizine HCl and 20–500 μg/mL for piracetam, with a mean accuracy of 100.03 ± 0.89 and 100.40 ± 0.94% for cinnarizine HCl and piracetam, respectively. The proposed procedures were checked using laboratory-prepared mixtures and successfully applied for the analysis of their pharmaceutical preparations. The validity of the proposed procedures was further assessed by applying the standard addition technique. Recoveries were quantitative, and the results obtained agreed with those obtained by other reported methods.