The success of organ transplant therapy depends in large part on the accurate and timely analysis of immunosuppressive drugs. In this study, we developed a fast, accurate method for the analysis of cyclosporin A, tacrolimus, sirolimus, and everolimus in whole blood. The method pairs a single precipitation step with LC-MS\/MS analysis using a Raptor Biphenyl column. A fast, 3-minute analysis time was obtained with no interference from matrix components. Excellent results were obtained for linearity, robustness, accuracy, and precision, demonstrating that the method is suitable for high-throughput therapeutic drug monitoring.<\/p>\n\n\n\n
Immunosuppressive drugs are used to suppress the body\u2019s immune response and are typically administered to prevent the rejection of transplanted organs or tissues. Cyclosporin A, tacrolimus, sirolimus, and everolimus are four of the most commonly used drugs in the therapy of organ transplantation. Their structures are shown in Figure 1. Cyclosporin A and tacrolimus are classified as calcineurin inhibitors, and sirolimus and everolimus are grouped as mTOR inhibitors. These two classes of drugs can be used in combination for synergistic blocking of T cell activation and proliferation. Due to their pharmacokinetic variabilities and narrow therapeutic indexes, time-sensitive and highly accurate therapeutic drug monitoring is necessary, not only to prevent rejection but also to minimize toxic side effects. Therefore, a fast and accurate measurement of drug concentration is critical to assist clinicians with timely and proper treatment of patients.<\/p>\n\n\n\n
Several commercial products are available for the simultaneous analysis of cyclosporin A, tacrolimus, sirolimus, and everolimus in whole blood. However, most of these commercial kits require an additional in-line trap column or SPE sample cleanup prior to chromatographic analysis. Here, we reduced sample preparation time and effort by pairing a single precipitation step with a Raptor Biphenyl analytical column. This analytical column was chosen because it provides suitable retention and selectivity for these compounds so that a short analysis time (3 minutes) can be achieved without encountering matrix interference. By combining a simple sample preparation step and a fast chromatographic elution, a high-throughput analysis was established for the simultaneous analysis of four immunosuppressive drugs in human whole blood.<\/p>\n\n\n