Effect of polyethylene glycol-2000 on amino acid surfactant-based vesicles.

Polyethylene glycol (PEG)-modified amino acid surfactant-based vesicles were prepared to improve the stability and cellular delivery of drugs. The vesicles comprised PEG-2000, sodium N-lauroylsarcosinate hydrate (SNLS), 1-decanol, and deionized water. The complex showed vesicular structures that were almost the same as the original vesicles, and their size distribution was (100-150 nm). Transmission electron microscopy (TEM) results revealed that no fusion occurred at 1.25 wt.% PEG concentration. The steric hindrance present among the vesicles prevented aggregation of the particles. No visual phase separation was observed for 6 months at room temperature 28 ºC. At higher molar concentration of PEG, fusion and wrinkling occurred owing to the association of PEG chains. The decreasing bending curvature led to the formation of fused vesicles with multilayer structure, as revealed by TEM and differential scanning calorimetry (DSC). [ABSTRACT FROM AUTHOR]