Solubilisation capacity of Brij surfactants

The aim of this study was to investigate the potential of selected Brij non-ionic surfactants for enhancing the solubility of poorly water-soluble drugs. Griseofulvin was selected as a model drug candidate enabling comparisons to be made with the solubilisation capacities of other poly(ethylene oxide)-based copolymers. UV/Vis and 1H NMR spectroscopies were used to quantify the enhancement of solubility of griseofulvin in 1 wt% aqueous micellar solutions of Brij 78 (C18H37E20), Brij 98 (C18H35E20) and Brij 700 (C18H37E100) (where E represents the OCH2CH2 unit of the poly(ethylene oxide) chain) at 25, 37 and 40 °C. Solubilisation capacities (Scp expressed as mg griseofulvin per g Brij) were similar for Brij 78 and 98 (range 6-11 mg g−1) but lower for Brij 700 (3-4 mg g−1) as would be expected for the surfactant with the higher ethylene oxide content. The drug loading capacity of micelles of Brij 78 was higher than many di- and triblock copolymers with hydrophilic E-blocks specifically designed for enhancement of drug solubility.

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