Phadungcharoen Noppharat, Pengwanput Natthapat, Nakapan Apisara, Sutitaphan Urassaya, Thanomklom Paweenut, Jongudomsombut Nut, Chinsriwongkul Akhayachatra, Rojanarata Theerasak
Pharmaceutical Development of Green Innovations Group (PDGIG), Faculty of Pharmacy, Silpakorn University, Sanam Chandra Palace Campus, Nakhon Pathom, 73000, Thailand.
Newcharoen Pharmaceutical L.P., Pathumthani, 12120, Thailand.
Talanta. 2020 Nov 1;219:121271. doi: 10.1016/j.talanta.2020.121271. Epub 2020 Jun 13.
Ion pair extraction coupled with digital image colorimetry has been developed as a promising platform for pharmaceutical analysis. The applicability of the approach was demonstrated through the assay of chlorpromazine hydrochloride tablets. In this method, the colorless, positively charged drug reacted with an anionic methyl orange dye in 1.5 mL microcentrifuge tubes, forming a yellow ion pair complex, which was extracted one time using a green solvent, i.e., ethyl acetate. Without the isolation or transfer of the liquid phase for dilution or measurement in a cuvette, a set of multiple tubes consisting of standards and samples were placed in a radial alignment above the white-light-illuminating screen of an iPad in a closed dark box and an image was taken in a single shot from the top of the box using an iPhone camera. The intensities of the yellow color of the extracts were transformed into red-green-blue (RGB) pixels using a mobile application, and the B values divided by the total of R + B + G were used as the analytical signals, which were plotted against the drug concentration to construct a standard curve. The proposed method showed good linearity (R = 0.9998) over the concentration range of 2.5-50 μg mL with a limit of quantitation of 2.30 μg mL. The proposed method was accurate, precise, and free from interferences by excipients used in tablets, thus yielding assay results with no significant difference from those analyzed using the United States Pharmacopeia 42 reference method. Moreover, the proposed method is exceptional because it can be rapidly and easily used, requires relatively inexpensive instrumentation, can be safely utilized by analysts, and is environmentally friendly. Therefore, the proposed assay platform has considerable potential for application to routine quality control and analysis of drug formulations in the pharmaceutical industry.
离子对萃取结合数字图像比色法已被开发成为一种很有前景的药物分析平台。通过盐酸氯丙嗪片的测定证明了该方法的适用性。在该方法中，无色带正电荷的药物在1.5 mL微量离心管中与阴离子甲基橙染料反应，形成黄色离子对络合物，用绿色溶剂（即乙酸乙酯）萃取一次。无需分离或转移液相进行稀释或在比色皿中测量，将一组由标准品和样品组成的多个试管以径向排列放置在封闭暗箱中iPad的白光照明屏幕上方，并用iPhone相机从箱顶一次性拍摄图像。使用移动应用程序将萃取物的黄色强度转换为红-绿-蓝（RGB）像素，并将B值除以R + B + G的总和作为分析信号，将其与药物浓度作图以构建标准曲线。所提出的方法在2.5-50 μg/mL的浓度范围内显示出良好的线性（R = 0.9998），定量限为2.30 μg/mL。该方法准确、精密，不受片剂中所用辅料的干扰，因此测定结果与采用美国药典42参考方法分析的结果无显著差异。此外，所提出的方法非常出色，因为它可以快速简便地使用，所需仪器相对便宜，分析人员可以安全使用，并且对环境友好。因此，所提出的分析平台在制药行业的药物制剂常规质量控制和分析中具有相当大的应用潜力。
