Thesis (M.Sc.)--Chulalongkorn University, 2011

In this work, encapsulation of ascorbyl palmitate (AP) into two polymeric nanoparticles, curcumin-grafted PV(OH) (Cur-PV(OH) and cinnamate-grafted PV(OH) (Cin-PV(OH), was carried out. The experiment covers polymer synthesis, particle fabrication, and encapsulation. Then, the stability of AP in the two polymeric nanoparticles and free AP in freeze-dried form and suspension form was investigated. The result showed that the encapsulated AP was more stable than the unencapsulated AP. AP in a freeze-dries form was more stable than AP in the suspension form. Moreover, AP kept under light-proof condition was more stable than that kept expected to light. AP inside the Cur-PV(OH) particles was more stable than AP co-encapsulated with curcumin inside the Cin-PV(OH) particles. Cur-PV(OH) nanospheres could be loaded with AP at the encapsulation efficiency of 80.85 ± 0.2%, at the loading of 29.00 ± 0.3% (wt of AP/total wt). An average diameter of AP-loaded Cur-PV(OH) particles was 269.80 ± 19.4 nm. The skin penetration study of AP-loaded Cur-PV(OH) particles on the ear skin of 6 month old pig using confocal laser fluorescence scanning microscope (CLFM) showed that hair follicle was the main skin penetrating routh of the AP-Cur-PV(OH) particles. Moreover, the accumulated Cur-PV(OH) at the hair follicles could release AP out into the surrounding tissue.