Capillary Electrophoresis With Contactless Conductivity Detection for Pharmaceutical Analysis: A Comprehensive Review

Capillary electrophoresis (CE) coupled with capacitively coupled contactless conductivity detection (CE-C⁴D) has emerged as a sensitive, versatile, cost-effective, and environmentally friendly technique for pharmaceutical analysis. The primary objective of this review is to critically evaluate pharmaceutical applications of CE-C⁴D, including active pharmaceutical ingredient (API) quantification, chiral separations, counter-ion analysis, and impurity and degradation product profiling. A concise and selective overview of CE-C⁴D fundamentals and key stages of its development-from early oscillometric detectors to advanced dual-axial designs-is provided solely to establish essential detection principles and to support discussion of method optimization, particularly the critical role of background electrolyte (BGE) selection. Summary tables compile BGE compositions and limits of detection (LODs), offering a comparative resource for researchers. Compared with conventional detectors such as ultraviolet (UV), fluorescence, and mass spectrometry (MS), CE-C⁴D enables universal and direct analysis of both UV-active and non-UV-active compounds, with additional advantages in portability and miniaturization.