Soudi Aya T, Hussein Ola G, Elzanfaly Eman S, Zaazaa Hala E, Abdelkawy Mohamed
Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Pharmaceutical Chemistry Department, Faculty of Pharmaceutical Science and Pharmaceutical Industries, Future University in Egypt, Cairo, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Oct 5;239:118516. doi: 10.1016/j.saa.2020.118516. Epub 2020 May 21.
Three univariate and two multivariate spectrophotometric methods were developed and subsequently validated to determine phenazopyridine HCl (PHZ) and trimethoprim (TMP) in the presence of 2,6-Diaminopyridine (2,6-DAP). The first univariate method depends on direct determination of phenazopyridine by measuring its absorbance at 412 nm and performed in concentration range of 1.00-10.00 μg/mL. Then the contribution of phenazopyridine is removed by dividing the mixture spectrum with PHZ divisor (5 μg/mL) after that the constant is mathematically subtracted and finally the generated spectrum is multiplied with the PHZ divisor. These steps eliminate PHZ contribution and the recovered spectrum is that of TMP and 2,6-DAP only where different methods can be applied to determine TMP and 2,6-DAP through this binary mixture spectrum. The first method to determine both components depends on measuring both TMP and 2,6-DAP through their first derivative (DD) spectra at 244.70 and 259.60 nm for TMP and 2,6-DAP, respectively with concentration ranges of 4.00-24.00 μg/mL TMP and 4.00-26.00 μg/mL 2,6-DAP. The second method depends on application of the isoabsorptive method which was used for TMP determination at its isoabsorptive point with 2,6-DAP at 242.64 nm with concentration range 1.00-20.00 μg/mL for TMP. The developed univariate methods were successfully applied to determine PHZ, TMP and PHZ impurity (2,6-DAP). Two multivariate methods were applied for determination of PHZ and TMP in presence of 2,6-DAP namely, Principle Component Regression (PCR) and Partial Least Squares (PLS). The results of the two models show that simultaneous determination of PHZ and TMP in presence of PHZ impurity can be performed in the concentration ranges of 6.00-14.00 μg/mL PHZ and 24.00-56.00 μg/mL TMP. All the proposed methods were successfully applied to analyze PHZ and TMP in pharmaceutical formulations without interference from the dosage form additives and the results were statistically compared with the reported method.
开发了三种单变量和两种多变量分光光度法，随后进行了验证，以测定在2,6 - 二氨基吡啶（2,6 - DAP）存在下的盐酸非那吡啶（PHZ）和甲氧苄啶（TMP）。第一种单变量方法是通过测量其在412nm处的吸光度直接测定非那吡啶，测定浓度范围为1.00 - 10.00μg/mL。然后，用PHZ除数（5μg/mL）除以混合物光谱以消除非那吡啶的贡献，之后进行数学减法运算并减去常数，最后将生成的光谱乘以PHZ除数。这些步骤消除了PHZ的贡献，得到的恢复光谱仅为TMP和2,6 - DAP的光谱，通过该二元混合物光谱可以应用不同方法测定TMP和2,6 - DAP。第一种同时测定两种成分的方法是通过分别测量TMP和2,6 - DAP在244.70nm和259.60nm处的一阶导数（DD）光谱来进行，TMP的浓度范围为4.00 - 24.00μg/mL，2,6 - DAP的浓度范围为4.00 - 26.00μg/mL。第二种方法依赖于等吸收点法，该方法用于在242.64nm处TMP与2,6 - DAP的等吸收点测定TMP，TMP的浓度范围为1.00 - 20.00μg/mL。所开发的单变量方法成功应用于测定PHZ、TMP和PHZ杂质（2,6 - DAP）。两种多变量方法，即主成分回归（PCR）和偏最小二乘法（PLS），用于在2,6 - DAP存在下测定PHZ和TMP。两个模型的结果表明，在存在PHZ杂质的情况下，可以在6.00 - 14.00μg/mL的PHZ和24.00 - 56.00μg/mL的TMP浓度范围内同时测定PHZ和TMP。所有提出的方法都成功应用于分析药物制剂中的PHZ和TMP，不受剂型添加剂的干扰，并且将结果与报道的方法进行了统计学比较。
