An HPLC with evaporative light scattering detection method for the quantification of PEGs and Gantrez in PEGylated nanoparticles

A rapid and precise HPLC method with evaporative light scattering detection (ELSD) for the separation and quantification of polyethyleneglycol 2000 (PEG 2000), polyethyleneglycoll 6000 (PEG 6000) and poly(methyl vinyl ether-co-maleic anhydride) (Gantrez) in a nanosized pharmaceutical formulation has been developed. Separation was carried out on a PL aquagel-OH 30,8 mu m column (300 mm x 7.5 mm), in a gradient elution with methanol-water as mobile phase at a flow rate of 1 ml/min. Quantification was determined in supernatants of PEGylated nanoparticles and the quantification limits were found to be 0.075 mg/ml for polyethyleneglycols and 0.25 mg/ml for Gantrez. The precision did not exceed 8% and accuracy range for PEGs (-11.50 and 10.61 %) and Gantrez (-12.18 and 14.81 %) were always within the acceptable limits. The amount of polyethyleneglycol associated to nanoparticles was also calculated by a Nuclear Magnetic Resonance Method (H-1 NMR). Likely, for both PEGs, a good relationship between both techniques was found. In summary, the developed HPLC technique provides an alternative for the routine and rapid analysis of PEGs and Gantrez in nanoparticle formulations. (c) 2007 Elsevier B.V. All rights reserved.