Analysis of immunosuppressive drugs and their pharmaceuticals by micellar electrokinetic chromatography

A simple and practical micellar electrokinetic capillary chromatography (MEKC) method is proposed for the quantitation of immunosuppressive drugs such as azathioprine (AZA), mycophenolate mofetil (MMF), cyclosporine A (CyA) and tacrolimus (FK 506). The electrophoretic separation of the analytes was performed with a background electrolyte containing 20 mM phosphate buffer a[ pH 75, 50 mM SDS and methanol as an organic modifier. Fused silica capillaries 75 mum i.d. and 60 cm in length were employed and detection of analytes was performed at 214 nm. Thorough validation according to international guidelines showed that the proposed method is reliable and appropiate for the routine analysis of immunosuppressants. Moreover, it may be an advantageous alternative to the traditional chromatographic methodologies currently employed in the pharmaceutical and bioanalysis fields.