LC-MS/MS method for the simultaneous quantitation of three active components derived from a novel prodrug against schistosome infection.

Schistosomiasis is an infectious disease that has been recognized as a severe health burden for some regions of the world. While praziquantel is the drug of choice, there is an unmet medical need for novel therapies with greater efficacy and resistant profile. DW-3-15 is a novel and promising prodrug possessing both adult and juvenile schistosomes killing capability. Its proposed hydrolytic products, artesunate (ARS), dihydroartemisinin (DHA) and 10-hydroxypraziquantel (10-OHPZQ), are all active in preventing schistosomal infection in relevant disease models. To support pharmacokinetic and PK-PD studies of DW-3-15, a simple, specific and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of the three active components in rat plasma. Using a short C18 column (2.1 mm × 50 mm, 5 µm) with linear gradient, a baseline resolution of the three analytes and corresponding internal standards was achieved with a total run time of 6 min. Mass detection was carried out by electrospray ionization in positive MRM mode with ion transitions of m/z 402.2→m/z 267.3 for ARS, m/z 302.2→m/z 163.1 for DHA, and m/z 329.2→m/z 219.4 for 10-OHPZQ. The method was linear over concentration ranges of 1.0-500 ng/mL for ARS, 5.0-2500 ng/mL for DHA, and 1.0-500 ng/mL for 10-OHPZQ. The accuracy was within ±10.0% for ARS, ±6.4% for DHA, and ±13.0% for 10-OHPZQ. The within-run and between-run precision of all three analytes at four concentrations tested were less than 15%, except at the LLOQ for DHA which was between 15 and 20%. The method was successfully applied to pharmacokinetic evaluation of DW-3-15 in rats following intravenous administration.