Gouda Ayman Abou El-Fetouh, El-Sheikh Ragaa, El Shafey Zeineb, Hossny Nagda, El-Azzazy Rham
Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt;
Int J Biomed Sci. 2008 Dec;4(4):294-302.
Rapid, simple and sensitive validated spectrophotometric methods have been described for the assay of pipazethate HCl (PiCl) and dextromethorphan HBr (DEX) either in pure form or in pharmaceutical formulations. The proposed methods were based on the oxidation of the studied drugs by a known excess of potassium permanganate in acidic medium and estimating the unreacted permanganate with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. Beer's law is obeyed in the concentration range of 2.0-16 and 2.0-15 μg mL(-1) for PiCl and DEX, respectively with correlation coefficient (n=6) ≥ 0.9993. The apparent molar absorptivity and sandell sensitivity values are in the range 1.062-1.484 × 10(4), 3.35-4.51 × 10(4) L mol(-1) cm(-1) and 29.36-41.03, 8.21-11.06 ng cm(-2) for PiCl and DEX, respectively. Different variables affecting the reaction were studied and optimized. The proposed methods were applied successfully to the determination of the examined drugs either in a pure or pharmaceutical dosage forms with good accuracy and precision. No interferences were observed from excipients and the results obtained were in good agreement with those obtained using the official methods.
已描述了快速、简便且灵敏的经验证的分光光度法，用于测定纯形式或药物制剂中的盐酸哌嗪乙胺（PiCl）和氢溴酸右美沙芬（DEX）。所提出的方法基于在酸性介质中用已知过量的高锰酸钾氧化所研究的药物，并在相同酸性介质中于合适的最大吸收波长（分别为521、485、610和664 nm）下，用苋菜红染料（方法A）、酸性橙II（方法B）、靛蓝胭脂红（方法C）和亚甲蓝（方法D）测定未反应的高锰酸钾。PiCl和DEX在浓度范围分别为2.0 - 16和2.0 - 15 μg mL⁻¹时符合比尔定律，相关系数（n = 6）≥ 0.9993。PiCl和DEX的表观摩尔吸光率和桑德尔灵敏度值分别在1.062 - 1.484 × 10⁴、3.35 - 4.51 × 10⁴ L mol⁻¹ cm⁻¹和29.36 - 41.03、8.21 - 11.06 ng cm⁻²范围内。研究并优化了影响反应的不同变量。所提出的方法已成功应用于纯形式或药物剂型中被测药物的测定，具有良好的准确度和精密度。未观察到辅料的干扰，所得结果与使用官方方法获得的结果高度一致。
