Storage Stability of Alpha-Lipoic Acid-loaded Lipid Nanoparticles

Alpha-lipoic acid-loaded lipid nanoparticles (ALA-LNs) were prepared by high pressure homogenization method. The influences of storage conditions such as time and temperature on the physical and chemical storage stability of ALA-LNs were studied in details. The stability was evaluated by particle size and polydispersity index, morphology of ALA-LNs, and capacity of ALA loading. The dilution and pH stability of ALA-LNs suspensions were also studied. After three months storage, the mean size of ALA-LNs at 4 and 40℃ was increased by 2.68% and 3.62% compared with the original size, respectively. ALA-LNs stored at 40℃ had ellipsoid shape and the mean size was about 152 nm (SD=23.6). The loading capacity of ALA at 40℃ was much higher than those stored at other two temperatures. The good dilution and pH stability were also demonstrated. The sample had good fluidity even at 4℃.