Lotfy Hayam M, Hegazy Maha A, Mowaka Shereen, Mohamed Ekram Hany
Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt.
Analytical Chemistry Department, Faculty of Pharmacy, British University in Egypt, 11837 El-Sherouk City, Egypt; Analytical Chemistry Department, Faculty of Pharmacy, Helwan University, Ein Helwan, 11795 Cairo, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Apr 5;140:495-508. doi: 10.1016/j.saa.2014.12.096. Epub 2015 Jan 5.
This work represents a comparative study of two smart spectrophotometric techniques namely; successive resolution and progressive resolution for the simultaneous determination of ternary mixtures of Amlodipine (AML), Hydrochlorothiazide (HCT) and Valsartan (VAL) without prior separation steps. These techniques consist of several consecutive steps utilizing zero and/or ratio and/or derivative spectra. By applying successive spectrum subtraction coupled with constant multiplication method, the proposed drugs were obtained in their zero order absorption spectra and determined at their maxima 237.6 nm, 270.5 nm and 250 nm for AML, HCT and VAL, respectively; while by applying successive derivative subtraction they were obtained in their first derivative spectra and determined at P230.8-246, P261.4-278.2, P233.7-246.8 for AML, HCT and VAL respectively. While in the progressive resolution, the concentrations of the components were determined progressively from the same zero order absorption spectrum using absorbance subtraction coupled with absorptivity factor methods or from the same ratio spectrum using only one divisor via amplitude modulation method can be used for the determination of ternary mixtures using only one divisor where the concentrations of the components are determined progressively. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. Moreover comparative study between spectrum addition technique as a novel enrichment technique and a well established one namely spiking technique was adopted for the analysis of pharmaceutical formulations containing low concentration of AML. The methods were validated as per ICH guidelines where accuracy, precision and specificity were found to be within their acceptable limits. The results obtained from the proposed methods were statistically compared with the reported one where no significant difference was observed.
本研究对两种智能分光光度技术进行了比较，即连续分辨率法和渐进分辨率法，用于同时测定氨氯地平（AML）、氢氯噻嗪（HCT）和缬沙坦（VAL）的三元混合物，无需预先分离步骤。这些技术由几个连续步骤组成，利用零级光谱、比率光谱和/或导数光谱。通过应用连续光谱减法结合常数乘法法，在零级吸收光谱中获得了所研究的药物，并分别在其最大吸收波长237.6nm、270.5nm和250nm处对AML、HCT和VAL进行测定；而通过应用连续导数减法，在一级导数光谱中获得了这些药物，并分别在P230.8 - 246、P261.4 - 278.2、P233.7 - 246.8处对AML、HCT和VAL进行测定。在渐进分辨率法中，使用吸光度减法结合吸光系数法从相同的零级吸收光谱中逐步测定各组分的浓度，或者通过仅使用一个除数的振幅调制法从相同的比率光谱中逐步测定各组分的浓度，从而实现对三元混合物的测定。所提出的方法通过实验室配制的混合物进行了验证，并成功应用于含有上述药物的药物制剂分析。此外，采用光谱添加技术（一种新型富集技术）与成熟的加样技术进行比较研究，用于分析含有低浓度AML的药物制剂。这些方法按照ICH指南进行了验证，发现准确度、精密度和专属性均在可接受范围内。将所提出方法得到的结果与已报道的结果进行了统计学比较，未观察到显著差异。
