Application of a new adhesive elastomeric coating and hydrophilic-lipophilic-balanced sorbent for modified stir-bar sorptive extraction.

A new polyurethane adhesive was evaluated to fix a hydrophilic-lipophilic-balanced sorbent and to produce modified stir-bars. It presented high mechanical and chemical resistance, indicating that it is an adequate adhesive. The homemade bars were employed to determine bisphenol A, diclofenac, ibuprofen and triclosan in aqueous medium. Satisfactory figures of merit were observed, with LOD between 0.06 and 0.30 ng mL-1 and enrichment factors between 133 and 195 times, using an extraction time of 2 h. The stir-bars were employed to determine the four analytes in water samples, presenting recovery results from 53 to 135% and RSD between 0.7 and 20%. In general, the results observed here indicated that the adhesive is an appropriate alternative material to fix HLB particles, and could probably be applied to other sorbents.

Hydrophilicity improvement of mercerized bacterial cellulose films by polyethylene glycol graft.

In this work, polyethylene glycol (PEG), of tree distinct molar masses (200, 300 and 400 g mol(-1)), was grafted onto mercerized bacterial nanocellulose (BNCm) and applied to produce nanofilms (BNCm-PEG). The products BNCm-PEG were characterized by NMR and thermal analysis. Solid-state NMR and X-ray diffraction analyses exhibited no significant differences in index of BNCm-PEG derivatives compared to BNCm, indicating that grafting reaction did not modify the BNCm crystalline structure. The apparent contact angle of the films showed that BNCm-PEG films exhibited a pronounced increase in the polar components (BNCm: 8.1 mN m(-1) vs BNCm-PEG400: 29.4 mN m(-1)), and a decrease in dispersive components (BNCm: 41.7 mN m(-1) vs BNCm-PEG400: 35.2 mN m(-1)) of the surface free energy. The BNCm-PEG films were more hydrophilic than BNCm and retained the biocompatibility with L929 fibroblast cells culture.

Enhanced gastric tolerability and improved anti-obesity effect of capsaicinoids-loaded PCL microparticles.

Capsaicinoids show several pharmacological effects including weight loss. However, their pungency limits the long-term use through the gastrointestinal tract. In that sense, the goal of this study was to prepare capsaicinoids-loaded poly(ε-caprolactone) microparticles as an oral carrier in order to improve their gastric tolerability and to make feasible the long-term treatment of obesity. Formulations containing 3, 5 and 10% capsaicinoids were successfully obtained by simple emulsion/solvent evaporation method. Values of encapsulation efficiency above 90% were achieved. Microparticles showed spherical shape and smooth surface. The particle size was suitable for oral use in order to provide an extended release through the gastrointestinal tract. No chemical bond was observed between drug and polymer. Microencapsulation led to drug amorphization. Formulations prolonged the release of capsaicinoids without changing the release kinetic (biexponential model). Microencapsulation increased the gastric tolerability of capsaicinoids because it prevented inflammatory processes in the stomach of rats. Microparticles containing 5% capsaicinoids demonstrated a statistically significant reduction of Lee index, mesenteric and retroperitoneal fat pads of rats with obesity induced by hypothalamic lesion using monosodium l-glutamate. In summary, capsaicinoids-loaded poly(ε-caprolactone) microparticles are low-irritative oral controlled-release carriers for a long-term use in obesity.