Comparative study of A HPLC–MS assay versus an UHPLC–MS/MS for anti-tumoral alkyl lysophospholipid edelfosine determination in both biological samples and in lipid nanoparticulate systems

The anti-tumor agent edelfosine represents a promising option in the treatment of cancer due to its capacity of promoting apoptosis in tumor cells selectively, while sparing healthy ones. In the present study, a novel ultra high performance liquid chromatography–tandem mass spectrometry method (UHPLC–MS/MS) was developed to quantify edelfosine concentrations in biological matrices (plasma, tissues or tumor) and in lipid nanoparticles, and compared with a conventional high performance liquid chromatography–mass spectrometry method (HPLC–MS). Compared with the HPLC method, the UHPLC method offered a threefold decrease in retention time, and a twofold decrease in asymmetry USP factor. Both methods were validated. Calibration curves for the HPLC method (0.1–1 and 1–75 μg/mL range in the plasma samples, 1–75 μg/mL range in lipid nanoparticle samples and 0.2–31.75 μg/mL range in tissue homogenate samples), and UHPLC method (0.0075–75 μg/mL for all kind of samples) showed a linear range of detector response (r > 0.999). Intra-batch and inter-batch precision ranged from 1.66% to 7.77% for the HPLC method and from 3.72% to 12.23% for the UHPLC method. Accuracy of the HPLC and UHPLC assays, expressed as bias, ranged from −5.83% to 7.13% and from −6.84% to 6.49%, respectively. Matrix effects on edelfosine were similar in the HPLC and UHPLC methods. The assay methods developed were successfully applied to the quality control procedure of the manufacture of edelfosine lipid nanoparticles, and to evaluate the pharmacokinetic and in vivo tissue distribution in mice after oral administration of edelfosine-loaded lipid nanoparticles. A good correlation between both techniques was found (r = 0.953) when tissue samples were analyzed with both methods.