Solubilidade da griseofulvina e estudo micelar dos polímeros: PVP K30/PVP K90/ PEG 35K/ F127 e das misturas: (F127/PVP K30), (F127/PVP K90) e (F127/PEG 35K)

Abstract

Griseofulvin is an antifungal dmg that could be isolated irom Penicillium griseofulvum Dierckx or synthesized. A major problem in the drug administration is its low aqueous solubility. Solubilization methods could be developed to solve this problem one alternative could be the application of block copolymers with surfactant properties. This is the fast work about the effect of PVP addition in the formation of F 127 gel solution which could be compared with the results described in the literature for PEG. The aim of this work was to investigate the copolymers PVP K30, PVP K90, PEG 35K and its mixtures with EçgPópEçg (Lutrol® F 127) as systems for solubilization of the hydrophobic dmg griseofülvin. The copolymers and their mixtures were characterized by small-angle X-ray scattering, dynamic light scattering and rheology. Tube inversion technique was used to study its gelling properties. The solubility of the dmg Griseofulvin in the micellar mixtures was measured by UV-Vis spectrophotometry and particle size by dynamic light scattering. In this work, dynamic light scattering from dilute solutions was used to check micellisation. Gel bounderies were defined by tube inversion (TI) and checked by oscillatore shear rheometry, thus distinguishing hard gel (immobile m the TI test) from soft gel (mobile but with raised elastic modulus). Elastic and viscous moduli were measured within the temperature range 5-80 °C, and SAXS was used to check gel stmcture at 30 C. The copolymers mixtures of PVP K30, PVP K90 and PEG 3 5 K with F 127 are promising systems for administration of hydrophobic drug griseofulvin because of their good values of solubilization capacity and preserved the useful thennoresponsive gelling properties ofF127. The mixture F127/PEG 35K showed the best result for griseofulvin solubilization in a low surfactant concentration system.