The effect of water-soluble polymers, PEG and PVP, on the solubilisation of griseofulvin in aqueous micellar solutions of Pluronic F127

The purpose of this study was to investigate the possibility of enhancing the solubilisation capacity of micellar solutions of Pluronic F127 for the poorly water-soluble drug griseofulvin by co-formulating with a water-soluble polymer. The effect of the addition of the polyethylene glycols PEG6000 and 35000, and the poly(vinylpyrrolidone)s PVP K30 and K90, on the solubilisation capacity of 1wt% solutions of Pluronic F127 was related to the effect of these additives on particle size as determined by dynamic light scattering measurements. The addition of PEG35000 to 1wt% F127 solutions significantly increased the solubility capacity expressed in terms of unit weight of F127; PVP K90 had a smaller effect but no enhancement was noted following the addition of PEG6000 or PVP K30. Solubilisation enhancement was thought to be a consequence of the association of the polymers with the E-blocks of the micelle corona so providing an expanded region of reduced polarity for drug solubilisation.