A reliable high-performance liquid chromatography assay for high-throughput routine cyclosporin A monitoring in whole blood.

Abstract

We report here a reliable high-performance liquid chromatography-ultraviolet assay for routine assay of cyclosporin A (CsA) in whole blood using solid-phase extraction. This assay is linear, between 20 and 2,000 micrograms/L, with correlation coefficients > 0.998 for five consecutive standard curves. All coefficients of variation (CV) were < 8% at CsA concentrations of 45, 480, and 1,800 micrograms/L, with the exception of the between-day CV at 45 micrograms/L, which was < 15%. The relative accuracy of the method is > 94% at 45, 480, and 1,800 micrograms/L. The mean recoveries for CsA and cyclosporin D (internal standard) were 38.2 +/- 4.8% (n = 45) and 40.1 +/- 6.7% (n = 45), respectively. This method has proven to be reliable and robust in a high-throughput therapeutic drug monitoring laboratory.