Development and validation of an LC-MS/MS method for the quantification of goserelin in a Pheroid® formulation, in simulated intestinal fluid

The purpose of this reported study was to develop and validate an LC-MS/MS method for the quantification of goserelin in a Pheroid (R) formulation simulated intestinal fluid. Biopharmaceuticals are formulated in drug delivery systems to improve their gastrointestinal stability. Goserelin, a peptide drug was formulated in Pheroid (R) delivery system and its gastrointestinal stability assessed using simulated intestinal fluid, which required an assay to determine the varying amounts of goserelin remaining after a specific time. Several extraction methods and solvents investigated to extract goserelin from complex matrix led to either poor recovery, peak shape or high background interference. A rapid gradient reversed-phase method coupled to tandem mass spectrometry detection was optimized for the separation and quantification of the extracted peptide. A simple, reproducible and good recovery extraction procedure for goserelin quantification was achieved through simultaneous acetonitrile protein precipitation and water-saturated n-butanol liquid-liquid extraction with water dilution. The method was found to be rapid, specific, precise and accurate, and successfully applied to determine goserelin remaining content in a simulated intestinal fluid, with potential use in other lipid-based formulation evaluated in simulated intestinal fluids. (C) 2019 Elsevier B.V. All rights reserved