Sunflower-oil-based lecithin organogels as matrices for controlled drug delivery

In this study, we dealt with the development of lecithin-based organogels using sunflower oil as the apolar phase. Metronidazole (MZ) was used as a model drug. The organogels were characterized by microscopy (light and phase contrast), Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, rheology, alternating-current impedance, hemocompatibility, antimicrobial analysis, and in vitro drug release. Microscopic analysis revealed the presence of spherical reverse micellar structures. There was an increase in the intermolecular hydrogen bonding among the gel components and crystallinity as MZ was incorporated into the organogels. The pH of the gel indicated that the gel may be nonirritant in nature and was hemocompatible. The release of MZ from the organogels followed Higuchi kinetics and was governed by anomalous or non-Fickian transport. The drug-loaded organogels showed antimicrobial activity against Bacillus subtilis, a Gram-positive bacteria. The preliminary results indicate that the developed organogel may be used as drug-delivery vehicle. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013