Amin Alaa S
Chemistry Department, Faculty of Science, Benha University, Benha, Egypt.
J Pharm Biomed Anal. 2002 Jul 20;29(4):729-36. doi: 10.1016/s0731-7085(02)00035-3.
New spectrophotometric procedures have been established for the quantitation of piroxicam and tenoxicam. The procedures are based on the reaction between the examined drug and alizarin (I), alizarin red S (II), alizarin yellow G (III) or quinalizarin (IV) producing ion-pair complexes which can be measured at the optimum wavelength. The optimization of the reaction conditions is investigated. Beer's law is obeyed in the concentration ranges 0.05-2.40 microg ml(-1), whereas optimum concentration as adopted from Ringbom plots was 0.12-2.25 microg ml(-1). The molar absorptivity, Sandell sensitivity, detection and quantification limits are also calculated. The correlation coefficient was >/=0.9990 (n=10) with a relative standard deviation (R.S.D.) of </=1.2, for ten determinations of 1.0 microg ml(-1). The methods are successfully applied to the determination of piroxicam and tenoxicam in their pharmaceutical formulations.
已建立了用于定量测定吡罗昔康和替诺昔康的新分光光度法。这些方法基于被测药物与茜素（I）、茜素红S（II）、茜素黄G（III）或醌茜素（IV）之间的反应，生成可在最佳波长下测量的离子对络合物。研究了反应条件的优化。在0.05 - 2.40微克/毫升（-1）的浓度范围内符合比尔定律，而从林邦曲线采用的最佳浓度为0.12 - 2.25微克/毫升（-1）。还计算了摩尔吸光率、桑德尔灵敏度、检测限和定量限。对于1.0微克/毫升（-1）的十次测定，相关系数≥0.9990（n = 10），相对标准偏差（R.S.D.）≤1.2。这些方法已成功应用于药物制剂中吡罗昔康和替诺昔康的测定。
