Physicochemical characterization and cytotoxic studies of nonionic surfactant vesicles using sucrose esters as oral delivery systems

VALDES KARINA, MORILLA MARIA JOSE, ROMERO EDER LILIA, CHAVEZ JORGE

COLLOIDS AND SURFACES B-BIOINTERFACES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 117 p. 1 - 6

0927-7765

Several nanotechnological solutions for mucosal immunization have been studied, such as nanoparticles, liposomes, solid lipidic particles, micelles, and surfactant vesicles. In recent years, surfactant vesicles have gainedincreasing scientific attention as an alternative potential drug delivery system to the conventional liposome. This type of vesicle known as niosomes or nonionic surfactant vesicles (NSVs) has a structure and properties similar to those of liposomes. Both of them cantransport hydrophilic drugs by encapsulation in the water phase or hydrophobic drugs by intercalation into hydrophobic domains. The aim of this study was to evaluate vesicles formed by esters of sucrose as protective systems of bioactive molecules for oral administration. Vesicles were prepared using two commercial products formed by mixtures of mono and diesters S-570 and S-770, respectively. Vesicles were characterized by size and zeta potential; the stability of formulations was assayed using a surfactant, and pH characteristic of different areas of the gastrointestinal tract too were measured. Moreover, Caco-2 cells were used to evaluate the cytotoxicity of vesicles and each raw material separately. The results showed no changes in size when the vesicles formed with both ester mixtures were exposed to 24.6 mM of triton X and to pH 5 and 7.4 up to 90 min. However, both formulations showed colloidal instability against acid pH, being a dramatic increase in size, as close to pH 2,which is the isoelectric point of the vesicles. Cytotoxic evaluation indicated that the vesicles were safe for the Caco-2 viability; however, sucrose monostearate as raw material was toxic for the cells but not when the sucrose distearate as raw material was assayed. As a conclusion of these preliminary studies, vesicles formed with the mixtures of sucrose esters showed a size in the range of 200 nm and maintained size when exposed to the action of a surfactant, but showed an increase in size at acidic pH.