Simultaneous determination of 2′,3′-dideoxyinosine and the active metabolite, 2′,3′-dideoxyadenosine-5′-triphosphate in human peripheral-blood mononuclear cell by HPLC–MS/MS and the application to cell pharmacokinetics

• DdI and ddA-TP in human PBMC was determined by HPLC-MS/MS for the first time.
• HILIC column was applied for the retention of the highly polar analytes.
• The method was applied to support cell pharmacokinetics.

A specific and reliable HPLC-MS/MS method was developed and validated for the simultaneous determination of 2′,3′-dideoxyinosine (ddI) and the active metabolites, 2′,3′-dideoxyadenosine-5′-triphosphate (ddA-TP) in human peripheral-blood mononuclear cell for the first time. The analytes were separated on a HILIC column (100 mm × 2.1 mm, 1.7 μm) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was used for detection. The cell homogenates sample was prepared by the solid phase extraction. The calibration curves were linear over a concentration range of 0.5–200.0 ng/mL for ddI and 0.25–100.0 ng/mL for ddA-TP. The intra-day and inter-day precision was less than 15% and the relative error (RE) were all within ±15%. The validated method was successfully applied to assess the disposition characteristics of ddI and support cell pharmacokinetics after the patients with AIDS were orally administrated with ddI and tenofovir disoproxyl fumarate (TDF).