El-Kosasy Amira M, Salem Maissa Y, El-Bardicy Mohamed G, Abd El-Rahman Mohamed K
Ain Shams University, Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Cairo, Egypt.
J AOAC Int. 2009 Nov-Dec;92(6):1631-8.
Two pyridostigmine bromide (PB) selective electrodes were investigated with 2-nitrophenyl octyl ether as a plasticizer in a polymeric matrix of carboxylated polyvinyl chloride (PVC-COOH), based on the interaction between the drug solution and the dissociated COOH groups in the PVC-COOH. One of the sensors was fabricated by using PVC-COOH only as anionic site without incorporation of an ionophore (sensor 1). The second sensor was constructed by using 2-hydroxy propyl beta-cyclodextrin as an ionophore (sensor 2). Linear responses of PB within a concentration range of 10(-3)-10(-2) and 10(-5)-10(-2) M, with slopes of 51.9 +/- 0.31 and 56.7 +/- 0.40 mV/decade over pH range of 5-10 were obtained using sensors 2 and 1, respectively. The proposed method displayed useful analytical characteristics for determination of PB in tablets with average recoveries of 100.22 +/- 0.62, and 100.15 +/- 0.72, and in plasma with average recoveries of 99.14 +/- 1.19 and 99.79 +/- 0.72, for sensors 2 and 1, respectively. The utility of 2-hydroxy propyl beta-cyclodextrin as an ionophore has a significant influence on increasing both membrane sensitivity and selectivity of sensor 2 in comparison with sensor 1. The methods were also used to determine the intact drug in the presence of its degradate, and thus could be used as stability-indicating methods. The results obtained by the proposed procedures were statistically analyzed and compared with those obtained by the U.S. Pharmacopeia method. No significant difference for either accuracy or precision was observed.
基于药物溶液与羧化聚氯乙烯（PVC - COOH）中解离的COOH基团之间的相互作用，研究了以2 - 硝基苯基辛基醚为增塑剂、羧化聚氯乙烯（PVC - COOH）为聚合物基质的两种溴化吡啶斯的明（PB）选择性电极。其中一个传感器仅使用PVC - COOH作为阴离子位点，不掺入离子载体（传感器1）。第二个传感器通过使用2 - 羟丙基 - β - 环糊精作为离子载体构建（传感器2）。分别使用传感器2和传感器1在5 - 10的pH范围内获得了PB在10(-3)-10(-2)和10(-5)-10(-2) M浓度范围内的线性响应，斜率分别为51.9±0.31和56.7±0.40 mV/十倍浓度变化。所提出的方法对片剂中PB的测定显示出有用的分析特性，传感器2和传感器1的平均回收率分别为100.22±0.62和100.15±0.72，对血浆中PB的平均回收率分别为99.14±1.19和99.79±0.72。与传感器1相比，2 - 羟丙基 - β - 环糊精作为离子载体对提高传感器2的膜灵敏度和选择性有显著影响。这些方法还用于在其降解产物存在的情况下测定完整药物，因此可作为稳定性指示方法。对所提出程序获得的结果进行了统计分析，并与美国药典方法获得的结果进行了比较。在准确性或精密度方面均未观察到显著差异。
