A flow injection analysis/mass spectrometry method for the quantification of polyethylene glycol 300 in drug...

A direct flow injection analysis/mass spectrometry (FIA/MS) method was developed for the quantification of polyethylene glycol. The method was used for the evaluation of distribution uniformity and mixing homogeneity of polyethylene glycol 300 (PEG 300) as a component in drug formulation mixtures. In the method, five of the most intense ions of the PEG 300 oligomer were chosen for selected ion monitoring (SIM) by mass spectrometry. Standard calibration curves were established, using either single channel SIM or the summed intensity of all five SIM channels plotting against the standard concentrations. Both calibration approaches produced comparable results on quantification. The feasibility of the method was demonstrated using both atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI). The method provided fast and sensitive quantification of PEG 300 without tedious chromatographic separation or sample preparation. The method has been successfully adopted for the evaluation of the mixing process in drug formulations.