A New Nanoparticulate System Based on Divanillin‐Crosslinked Starch: Mode of Manufacturing and In‐Vitro Evaluation of Skin Penetration

Starch nanoparticles (SNPs) attract special attention due to their natural origin as well as their biodegradable and biocompatible properties. Nanoparticles based on divanillin‐modified starch loaded with curcumin are manufactured through a simple procedure of nanoprecipitation by either the solvent dropping process or the non‐solvent dropping process, without any stabilizing agent. Curcumin loading is increased with divanillin concentration, and the entrapment efficiency for 15% divanillin‐crosslinked SNPs is determined as 58.7% ± 9.6% (15.6 ± 2.5 µg mg−1 lyophilized SNPs). Since the process uses gelatinized starch, retrogradation is evidenced by DSC thermograms of the SNPs. The DSC profiles of re‐gelatinization show three endothermic transitions which are dependent on the divanillin level. This study demonstrates that dermal application of curcumin‐containing SNPs crosslinked by 10% and 15% divanillin results in a significantly enhanced penetration of curcumin into porcine ear skin compared to the non‐crosslinked SNPs and 5% crosslinked SNPs. The study concludes therefore that the crosslinking method based on divanillin reaction with starch influences the encapsulation of curcumin in the SNPs and the ability of loaded SNPs to enhance curcumin penetration into the skin. Divanillin‐crosslinked starch nanoparticles (SNPs) were fabricated to effectively encapsulate curcumin by the nanoprecipitation method using a non‐solvent dropping process. Curcumin loading in the SNPs and their entrapment efficiency were increased with the increase of the crosslinker concentration. Dermal application of curcumin‐containing SNPs crosslinked by 10%‐15% divanillin, resulted in a significantly enhanced penetration of curcumin into pig skin compared to non‐crosslinked SNPs.