Analytical Chemistry Department, Faculty of Pharmacy - Cairo University, Kasr Al-Aini Post, ET, 11562, Cairo, Egypt.
Analytical Chemistry Department, Faculty of Pharmacy - Cairo University, Kasr Al-Aini Post, ET, 11562, Cairo, Egypt.
Anal Chim Acta. 2022 Apr 1;1200:339599. doi: 10.1016/j.aca.2022.339599. Epub 2022 Feb 11.
Solid contact ion-selective electrodes (ISEs) have witnessed versatile applications in pharmaceutical and biological analysis however they suffer from some limitations. Besides formation of water layer, the doped ion exchanger in sensing membrane fails to distinguish between two ionic species having relatively similar lipophilicity and carrying same charges. Those shortcomings practically hampered the simultaneous determination of alfuzosin and solifenacin in their combined pharmaceutical combination. Hence, this paper was directed to develop two carbon paste electrodes allowing their simultaneous determination based on molecular imprinted polymers (MIPs). Efforts were firstly directed to stabilize the potential signals through synthesis of polyaniline (PANI) nanoparticles with 26 nm particle size as confirmed by means of UV-spectrophotometry, Zeta-sizer and transmission electron microscope. This was followed by its doping at electrode/ion selective membrane interface leading to diminished potential drift, better Nernstian slopes and lower limit of detections. Secondly, MIPs for each drug were prepared by precipitation polymerization technique and fully characterized by Fourier-transform infrared spectroscopy, field-emission scanning electron microscope, differential scanning calorimetry, surface area analysis and rebinding studies. The prepared MIPs were then incorporated in membrane cocktail and doped over PANI layer. The graved cavities inside MIPs act as synthetic host-tailored receptors that could recognize and bind specifically to each drug. The obtained Nernstian slopes were 57.16 mV/decade for alfuzosin MIP-based sensor and 58.17 mV/decade for solifenacin MIP-based one with respective LOD values of 7.9 × 10 M and 8.9 × 10 M. Moreover, no interference was ostensibly detected from dosage form excipients, plasma constituents or degradation products/official impurities allowing quantification of alfuzosin and solifenacin in their combined capsule, spiked human plasma and in presence of their degradation products.
固体接触离子选择性电极（ISE）在药物和生物分析中得到了广泛的应用，但它们也存在一些局限性。除了形成水层外，传感膜中的掺杂离子交换剂无法区分两种具有相似亲脂性且带相同电荷的离子。这些缺点实际上阻碍了它们在联合药物制剂中的同时测定。因此，本文旨在开发两种允许基于分子印迹聚合物（MIP）同时测定的碳糊电极。首先，通过使用紫外分光光度法、Zeta 粒度仪和透射电子显微镜，将聚（苯胺）纳米粒子的粒径稳定在 26nm，从而稳定了电位信号。然后将其掺杂到电极/离子选择膜界面，从而减少了电位漂移、更好的能斯特斜率和更低的检测限。其次，通过沉淀聚合技术制备了每种药物的 MIP，并通过傅里叶变换红外光谱、场发射扫描电子显微镜、差示扫描量热法、表面积分析和再结合研究对其进行了充分表征。然后将制备的 MIP 掺入膜混合物中并掺杂在 PANI 层上。MIP 内部的刻蚀空腔充当了合成的主体定制受体，可以特异性地识别和结合每种药物。基于 alfuzosin MIP 的传感器获得的能斯特斜率为 57.16 mV/decade，基于 solifenacin MIP 的传感器获得的能斯特斜率为 58.17 mV/decade，相应的检测限分别为 7.9×10 -7 M 和 8.9×10 -7 M。此外，从剂型赋形剂、血浆成分或降解产物/官方杂质中没有明显检测到干扰，从而允许在联合胶囊、加标人血浆中以及在其降解产物存在下定量测定 alfuzosin 和 solifenacin。
