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

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

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 proposed, such as nanoparticles, liposomes, solid lipidic particles, micelles, and surfactant vesicles. In recent years, surfactant vesicleshave gained increasing scientific attention as an alternative potential drug delivery system to the con-ventional liposome. This type of vesicle known as niosomes or nonionic surfactant vesicles (NSVs) has structure and properties similar to those of liposomes. Both of them can transport hydrophilic drugsby encapsulation in the aqueous inner pool or hydrophobic drugs by intercalation into hydrophobicdomains. The aim of this study was to prepare and characterize vesicles formed by sucrose esters asprotective systems of bioactive molecules for oral administration. Vesicles were prepared using twocommercial products formed by mixtures of mono and diesters S-570 and S-770, respectively. Determined parameters were size and zeta potential; the stability of formulations was tested in presence ofincreasing concentrations of a surfactant, and at several pH values observed in the gastrointestinal tract.Solubilization experiences showed an initial decrease in size for vesicles of both ester mixtures, samplesshowed detergent resistance at higher Triton X-100 concentrations. Vesicles showed stability at pH 5 and 7.4 up to 90 min; however, both formulations showed colloidal instability at pH 2, which corresponds to the isoelectric point of these vesicles. To evaluate the cytotoxicity of both vesicle formulations and separatelyeach pure ester, Caco-2 cells were used. Cytotoxic evaluation indicated that both types of vesicles andfree sucrose distearate were safe for Caco-2 viability; however, free sucrose monostearate was toxic forthe cells.As a conclusion of these preliminary studies, it can be stated that vesicles formed with mixtures of sucrose esters showed a size in the range of 200 nm maintaining their size when exposed to the action of a surfactant, but showing aggregation at acidic pH