Development of an Analytical Method Based on Capillary Electrophoresis for Simultaneous Quantification of Memantine and Donepezil in Anti-Alzheimer’s Pharmaceuticals

Abstract

In the study, a capillary electrophoresis method utilizing capacitively coupled contactless conductivity detection (CE-C⁴D) was developed and evaluated for the simultaneous analysis of memantine (MEM) and donepezil (DON) in pharmaceutical samples for Alzheimer’s disease treatment. The analytical conditions were established, including a background electrolyte (BGE) composed of 1.0 M acetic acid, a separation voltage of -22 kV, and siphonic sample injection at a height of 10 cm for 60 seconds. Under these conditions, the limits of detection (LOD) for MEM and DON were 0.59 mg/L and 1.39 mg/L, respectively. The relative standard deviations (RSD) for peak area and migration time were less than 6% and 1%, respectively, in intra-day repeatability assessments (n = 7), and less than 8% and 4%, respectively, in inter-day reproducibility assessments (n = 5) for mixed standard samples at a concentration of 20 mg/L. The recovery efficiency for both analytes in spiked standard matrices ranged from 94 to 108%. The CE-C⁴D method was applied to analyze two real pharmaceutical samples containing DON as the main active ingredient, and the results indicated that the difference between the content determined by CE-C⁴D and the manufacturer’s labeled content was less than 10%.