Characterization and molecular weight determination of water-soluble polyethylene glycol oligomers using open-tubing liquid chromatography—mass spectrometry

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

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.

The identification of polyoxyethylene glycols and related compounds by capillary gas chromatography

A sample work-up method for gas chromatographic profiling of polyoxyethylene glycol (PEG)-related compounds in pharmaceutical matrices is described. After a short sample clean-up, carbon-oxygen linkages are partially cleaved with 0.07 M boron tribromide in dichloromethane at room temperature. The reaction is stopped after 1 min by addition of 0.01 M HCl. The products are trimethylsilylated and injected onto a WCOT 50 m x 0.25 mm CP-SIL 5 CB fused silica column. Eleven model compounds, representing four common types of PEG-derivatives, have been evaluated by this method. The results show that characteristic profiles can be obtained from PEG-derivatives carrying different functional groups. Minimum detectable amounts are in the range of 200 micrograms.