Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, 71526, Egypt.
J Fluoresc. 2013 Nov;23(6):1301-11. doi: 10.1007/s10895-013-1264-0. Epub 2013 Jul 20.
A rapid, sensitive and selective flow injection analysis (FIA) method was developed for the determination of some selective α1-blockers including; terazosin (TER), doxazosin (DOX), prazosin (PRZ), and alfuzosin (ALF). The method was based on enhancement of the native fluorescence of the studied drugs in the presence of sodium dodecyl sulfate (SDS). The method was optimized for the buffer type, concentration and pH, surfactant type and concentration, flow rate and detection wavelengths in order to achieve the maximum sensitivity. The results showed that the best sensitivity was obtained by using SDS (10 mM) in phosphate buffer (20 mM, pH = 3), flow rate was 0.5 ml/min and the detector was set at λex = 250 and λem = 389. Under these optimum conditions there was a linear relationship between the concentration and the fluorescence intensity in the range from 5-400 ng ml(-) with correlation coefficient of more than 0.998. The detection and quantitation limits for the studied drugs by the proposed method were 3.2-11.9 ng ml(-1) and 10.8-39.7 ng ml(-1), respectively. The method was validated in accordance with the requirements of ICH guidelines and shown to be suitable for intended applications. Moreover, the binding constants for α1-blockers -SDS system were determined using the adduct model. The proposed method has been applied successfully for the analysis of the pure forms for studied drugs and also their pharmaceutical formulations and the results were compared with official methods.
建立了一种快速、灵敏和选择性的流动注射分析（FIA）方法，用于测定一些选择性α1受体阻滞剂，包括特拉唑嗪（TER）、多沙唑嗪（DOX）、哌唑嗪（PRZ）和阿夫唑嗪（ALF）。该方法基于在十二烷基硫酸钠（SDS）存在下，研究药物的固有荧光增强。为了获得最大的灵敏度，对缓冲液类型、浓度和 pH 值、表面活性剂类型和浓度、流速和检测波长进行了优化。结果表明，在磷酸盐缓冲液（20 mM，pH = 3）中使用 SDS（10 mM）、流速为 0.5 ml/min 且检测器设置在 λex = 250 和 λem = 389 时，灵敏度最佳。在这些最佳条件下，浓度与荧光强度之间存在线性关系，线性范围为 5-400 ng ml(-1)，相关系数大于 0.998。该方法对研究药物的检测限和定量限分别为 3.2-11.9 ng ml(-1)和 10.8-39.7 ng ml(-1)。该方法按照 ICH 指南的要求进行了验证，证明适用于预期应用。此外，还使用加合物模型确定了 α1 受体阻滞剂-SDS 体系的结合常数。该方法已成功应用于研究药物的纯形式及其制剂的分析，并将结果与官方方法进行了比较。
