Amraei Ahmadreza, Niazi Ali
Department of Chemistry, Faculty of Science Islamic Azad University, Arak Branch, Arak, Iran.
Iran J Pharm Res. 2018 Fall;17(4):1191-1200.
In this study, the direct determination of cefixime as an anti-bacterial agent, in pharmaceutical formulations, urine and human blood plasma was conducted based on spectrophotometric measurements using parallel factor analysis (PARAFAC) and partial least squares (PLS). The calibration set was composed of fourteen solutions in the range of 0.50- 9.00 µg mL. PLS models were calculated at each pH applied to determine a set of synthetic cefixime solutions. The best model was acquired at pH 1.02 (PLS-pH 1.02). The ability of the method for the analysis of real samples was considered by determination of cefixime in pharmaceutical preparations, urine and plasma with satisfactory results. The calculated model with PARAFAC showed good prediction capability with root mean square error of prediction (RMSEP) of 0.12 for cefixime. The acid dissociation constants (p ) of cefixime play a fundamental role in the mechanism of activity of cefixime. The p of cefixime were estimated by DATAN program using the corresponding absorption spectra-pH data. The calculated p values of cefixime were 1.89 and 3.80 for p and p respectively.
在本研究中，基于使用平行因子分析（PARAFAC）和偏最小二乘法（PLS）的分光光度测量，对药物制剂、尿液和人体血浆中的抗菌剂头孢克肟进行了直接测定。校准集由14种浓度范围为0.50 - 9.00 µg/mL的溶液组成。在每个应用的pH值下计算PLS模型，以确定一组合成头孢克肟溶液。在pH 1.02时获得了最佳模型（PLS-pH 1.02）。通过测定药物制剂、尿液和血浆中的头孢克肟来评估该方法分析实际样品的能力，结果令人满意。用PARAFAC计算的模型对头孢克肟具有良好的预测能力，预测均方根误差（RMSEP）为0.12。头孢克肟的酸解离常数（pKa）在头孢克肟的活性机制中起基本作用。使用相应的吸收光谱-pH数据，通过DATAN程序估算头孢克肟的pKa值。头孢克肟的计算pKa值，pKa1和pKa2分别为1.89和3.80。
