Rahman Nafisur, Rahman Habibur, Azmi Syed Najmul Hejaz
Department of Chemistry, Aligarh Muslim University, Aligarh-202002 U.P., India.
Chem Pharm Bull (Tokyo). 2005 Aug;53(8):942-8. doi: 10.1248/cpb.53.942.
A kinetic spectrophotometric method has been described for the determination of metoprolol tartrate in pharmaceutical formulations. The method is based on reaction of the drug with alkaline potassium permanganate at 25+/-1 degrees C. The reaction is followed spectrophotometrically by measuring the change in absorbance at 610 nm as a function of time. The initial rate and fixed time (at 15.0 min) methods are utilized for constructing the calibration graphs to determine the concentration of the drug. Both the calibration graphs are linear in the concentration range of 1.46 x 10(-6)-8.76 x 10(-6) M (10.0-60.0 microg per 10 ml). The calibration data resulted in the linear regression equations of log (rate)=3.634+0.999 log C and A=6.300 x 10(-4)+6.491 x 10(-2) C for initial-rate and fixed time methods, respectively. The limits of quantitation for initial rate and fixed time methods are 0.04 and 0.10 microg ml(-1), respectively. The activation parameters such as E(a), DeltaH(double dagger), DeltaS(double dagger) and DeltaG(double dagger) are also evaluated for the reaction and found to be 90.73 kJ mol(-1), 88.20 kJ mol(-1), 84.54 J K(-1) mol(-1) and 63.01 kJ mol(-1), respectively. The results are validated statistically and through recovery studies. The method has been successfully applied to the determination of metoprolol tartrate in pharmaceutical formulations. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.
已描述了一种动力学分光光度法用于测定药物制剂中的酒石酸美托洛尔。该方法基于药物在25±1℃下与碱性高锰酸钾的反应。通过在610nm处测量吸光度随时间的变化进行分光光度监测反应。采用初始速率法和固定时间（15.0分钟）法构建校准曲线以确定药物浓度。两种校准曲线在1.46×10⁻⁶ - 8.76×10⁻⁶ M（每10ml含10.0 - 60.0μg）的浓度范围内呈线性。校准数据分别得出初始速率法和固定时间法的线性回归方程：log(速率)=3.634 + 0.999 log C和A = 6.300×10⁻⁴ + 6.491×10⁻² C。初始速率法和固定时间法的定量限分别为0.04和0.10μg ml⁻¹。还评估了该反应的活化参数，如E(a)、ΔH(双剑号)、ΔS(双剑号)和ΔG(双剑号)，分别为90.73 kJ mol⁻¹、88.20 kJ mol⁻¹、84.54 J K⁻¹ mol⁻¹和63.01 kJ mol⁻¹。结果通过统计学和回收率研究进行了验证。该方法已成功应用于药物制剂中酒石酸美托洛尔的测定。结果与参考方法的统计学比较显示出极好的一致性，表明在准确度和精密度方面无显著差异。
