To initiate our research into the development of biocompatiîle gelled-microemulsions based on essential oils (EOs) and sucrose esters (SEs) for the topical delivery of fluconazole, this formulation study investigated the usefulness of two relatively harmless natural non-ionic surfactants from the group of SEs (sucrose laurate and stearate) to form, in the presence of antifungal EOs, stable, isotropic microemulsions effective on fluconazole solubilization. Fluconazole’s solubility in EO significantly depended on their chemical composition, showing higher values for cinnamon, oregano and clove essential oils, further selected as oil phase components for microemulsion formulations. The phase behavior of several EO–isopropyl miristate/SE–isopropanol/water systems was assessed through pseudo-ternary phase diagrams constructed by microplate dilution technique. The hydrocarbon chain length of the SE and EO type strongly influenced the size of the microemulsion region in the pseudo-ternary phase diagrams. Ten microemulsion formulations containing 2% fluconazole, 6% or 10% oil mixture of EO–isopropyl myristate in 1:1 ratio, 45% SE-isopropanol mixture and water, were selected and evaluated for physicochemical properties (droplet size, polydispersity, viscosity, refractive index, zeta potential and pH). All formulations were physicochemically acceptable, but viscosity enhancement and further in vitro and in vivo tests are required for the development of biocompatible, clinically safe and effective fluconazole topical preparations.
The objectives of this study are the development and evaluation of modified release multi-particulate drug delivery systems containing a BCS class II drug (meloxicam), formulated as polymer-coated pellets. Inert seeds containing microcrystalline cellulose, lactose monohydrate, and polyvinylpyrrolidone were prepared by extrusion-spheronization. The obtained cores were loaded with meloxicam using the drug layering technique, by spray coating in a fluidized bed with a liquid dispersion of the drug. The resulting drug pellets were film-coated with various polymers (Acryl-EZE® 93O, Eudragit® RS 30-D as well as experimental composite obtained by adding Methocel™ E5 Premium LV as pore forming agent to the extended release polymer Eudragit® RS 30-D). All experimental systems were evaluated by scanning electron microscopy and in vitro release testing, in an attempt to investigate the characteristics of the film coatings and their influence on drug release from the multi-particulate systems. The in vitro release study was performed in two stages, using two media with pH values corresponding to the gastric and intestinal environment (HCl 0.1N, pH = 1.2 for the first two hours of the test and phosphate buffer 50 mM, pH 6.8 for the next 4 h). The in vitro release data have highlighted the impact of the formulation factors on the drug release.