Determination of the immunostimulatory drug - Glucosoaminyl-Muramyl-Dipeptide - in human plasma using high performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

INTRODUCTION MDP (glucosaminyl-muramyl-dipeptide), a synthetic analog of the peptidoglycan fragment of the bacterial cell wall, is an active component of the immunomodulatory drug Licopid®. But, the pharmacokinetic parameters of GMDP in humans after oral administration have not been investigated yet. A present study aimed to develop and validate a sensitive liquid chromatography-tandem mass spectrometry method for the analysis of GMDP in human plasma. METHODS Sample preparation was performed by solid-phase extraction using Strata-X 33um Polymeric Reversed Phase 60 mg/3ml cartridges. The separation of analytes was performed using an Acquity UPLC BEN C18 column 1.7 μm 2.1 x 100 mm (Waters, USA). GMDP and internal standard GHRP-2 (pralmorelin) were ionized in positive electrospray ionization mode and detected in multiple reaction monitoring mode. RESULTS The developed method was validated within a linear range of 50-3000 pg/mL for GMDP. Accuracy for all analytes, given as deviation between nominal and measured concentration and assay variability (CV) ranged from 1.61 % to 3.02 % and from 0.89 % to 1.79 % respectively both for within- and between-run variabilities. CONCLUSIONS The developed and validated HPLC-MS/MS method was successfully used to obtain the plasma pharmacokinetic profiles of GMDP distribution in human plasma.