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Microemulsions (MEs) and self-emulsifying drug delivery systems (SEEDS) containing phenobarbital (Phe) were developed to improve its chemical stability, solubilizing capacity and taste-masking in oral liquid dosage forms. Cremophor® RH40 and Labrasol® were used as surfactants for the screening of ME regions, Capmul® MCM L, Captex® 355, Imwitor® 408, Myglyol® 840 and Isopropyl myristate were the oil phases assayed; Transcutol® P, Polyethylene-glycol 400, glycerol, Propylene-glycol and ethanol the cosurfactants. Phe stability assay was carried out (20:4:20:56% and 20:4:35:41% (w/w); surfactant:oily phase:cosurfactant:water) for both surfactants; only one containing ethanol showed significant dismissing in its drug content. Solubility capacity for these selected formulations were also evaluated, an amount between 17 and 58 mg/mL of Phe could be loaded. At last, an optimized ME formulation with Cremophor® RH40 20%, Capmul® MCM L 4%, PEG 400 35% and sucralose 2% (w/w) was chosen in order to optimize taste-masking using an electronic tongue. Strawberry along with banana and tutti-frutti flavors plus mint flavor proved to be the best ones. Labrasol-based pre-concentrates were tested for (micro)emulsifying properties; all of them resulted to behave as SEDDS. In summary, a rationale experimental design conducted to an optimized ME for Phe oral pediatric administration which was able to load 5-fold times the currently used dose (4 mg/mL), with no sign of physical or chemical instability and with improved taste; SEDDS for capsule filling were also obtained. The biopharmaceutical advantages described for these dosage forms encourage furthering in vivo evaluation.

The aim of this work was to study the iron uptake of Caco-2 cells incubated with five different formulations of liposomes containing iron. The vesicles were also characterized before, during, and after in vitro digestion. Caco-2 cells were incubated with digested and nondigested liposomes, and soluble iron uptake was determined. Nondigested liposomes made with chitosan (CHI) or the cationic lipid, DC-Cholesterol (DC-CHOL), generated the highest iron uptake. However, these two formulations were highly unstable under in vitro digestion, resulting in nonmeasurable iron uptake. Digested conventional liposomes composed of soybean phosphatidylcholine (SPC), hydrogentated phosphatidylcholine (HSPC), or HSPC and cholesterol (CHOL) presented the highest iron-uptake values. These liposomal formulations protected iron from oxidation and improved iron uptake from intestinal cells, compared to an aqueous solution of ferrous sulphate.

Specific immunotherapy (SIT) is the only potentially curative treatment for those allergic processes mediated by IgE. We compared the effects of different SITs in mice sensitised with ovalbumin (OVA) Al (OH)(3) : 1) OVA entrapped in particles of poly (D,L-lactic-co-glycolic acid) (PLGA-OVA), 2) Soluble OVA (OVA-sol) and 3) Polymerised OVA (OVA-pol). Serum levels of specific IgE, IgG1, IgG2a and asymmetric IgG, the cutaneous anaphylaxis test (PCA), and the IL-10, IFNgamma and IL-4 levels in culture supernatants of splenocytes challenged with OVA were assessed. Mice treated with PLGA-OVA had higher levels of asymmetric antibodies than non-desensitised mice; a low IgG1 and high IgG2a level was observed together with inhibitory effect in the PCA reaction that reversed in the absence of asymmetric IgG. IL-10 and IFNgamma levels were higher in supernatants from mice treated with PLGA-OVA and OVA-sol than those obtained from non-desensitised controls. Our results suggest that among the different SITs evaluated, PLGA-OVA is the one that best showed an increase in the asymmetric IgG molecules and an effective deviation of the immune response. Furthermore, the increase in the proportion of asymmetric antibodies would be of importance when designing new vaccination strategies for allergy.

Microspheres of Bacillus subtilis were prepared using sodium alginate. Some typical properties of microencapsulated systems, such as microorganism content, particle size, and germination time, were studied. Calcium alginate microspheres were obtained by the emulsification method, dripping into a solution of calcium salt. The conditions of the preparation steps were very soft to produce calcium alginate microspheres containing cells with no apparent changes in general biological properties. The hydrogel matrix provides protection without preventing communication with the surrounding medium.