使用多變量校準方法決定 Levodopa 與 Carbidopa 同時測定動力學電位   全文下載

Simultaneous Kinetic-Potentiometric Determination of Levodopa and Carbidopa Using Multivariate Calibration Methods

Partial least squares（PLS）及principle component regression（PCr）多變量校準方法被應用在同時測定carbidopa 與levodopa，可從動力學數據採用新穎的電位方法。這方法是藉由carbidopa 與levodopa 在反應中監控N-chlorosuccinimide（NCS）產生氯離子的速率作為依據，實驗數據顯示ion-selective electrodes（ISes）不僅適合直接偵測氯離子而且可同時使用化學方法分析動力學電位，觀察不同氯離子產生速率得到結果，結果顯示同時偵測 carbidopa 與 levodopa 其濃度表現範圍分別是1.0 - 14.0 及0.5 - 25.0 μg/mL。將九個合成樣品應用PCr 及PLS 方法，carbidopa 濃度範圍2.0 - 13.0μg/mL 相對標準差4.81 而levodopa 濃度範圍1.0 - 18.0 μg/mL 相對標準差4.29。此作用確信賦形劑可作為影響反應速率的選擇性評估方法，這兩種方法（PLS 及PCr）可用來證實混合合成樣品及常見商業配方決定carbidopa與levodopa 濃度之套組，相較那些參考應用高效能液相層析方法，此法有較令人滿意的回收率。

Partial least squares (PLS) and principle component regression (PCR) multivariate calibration methods were applied to the simultaneous determination of carbidopa and levodopa using kinetic data from novel potentiometry methods. These methods were based on the rate of chloride ion production in the reaction of carbidopa and levodopa with N-chlorosuccinimide (NCS) which was monitored by a chloride ion-selective electrode. The experimental data shows suitability of ion-selective electrodes (ISEs) to be used as detectors not only for the direct determination of chloride ion but also for simultaneous kinetic-potentiometric analysis using chemometric methods. These methods are based on the differences observed in the production rate of chloride ions. The results show that simultaneous determination of carbidopa and levodopa can be performed in their concentration ranges of 1.0 - 14.0 and 0.5 - 25.0 μg/mL, respectively. The total relative standard errors for applying PCR and PLS methods to 9 synthetic samples in the concentration range of 2.0 - 13.0 μg/mL for carbidopa and 1.0 - 18.0 μg/mL for levodopa were 4.81 and 4.29, respectively. The effects of certain additives used as excipients upon the reaction rate were determined to assess selectivity of the method. Both methods (PLS and PCR) were validated using a set of synthetic sample mixtures and then were successfully applied to the determination of carbidopa and levodopa in several commercially available mixture formulations. The recoveries were satisfactory and comparable to those obtained by applying the reference Pharmacopoeia method of high performance liquid chromatography.