Enhanced Ascorbyl Palmitate Stability by Polymeric Nanoparticles

Ascorbyl palmitate (AP) loaded poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NP) were prepared by interfacial polymer deposition according to the solvent displacement method. The particle size varied from 115 to 150 nm (poydispersity index around 0.10) while the zeta potential was around - 30 mV for all formulations. In general, NP formulations exhibited a high AP encapsulation efficiency. Low temperature and pHs around neutrality increased the AP stability in both PLA and PLGA NP. However, PLA NP was more stable in distilled water than in diverse phosphate buffer systems elucidating an important effect of the ionic strength on the stability of AP Additional degassing of the distilled water led to the best AP protection in PLA NP even when stored under atmospheric condition. The degassing step and the polymer type were found to be essential for stabilization purposes. PLA NP demonstrated their potential as a promising formulation for increased AP stabilization.