Evaluation of Release Kinetics and Mechanisms of Curcumin and Curcumin--Cyclodextrin Inclusion Complex Incorporated in Electrospun Almond Gum/PVA Nanofibers in Simulated Saliva and Simulated Gastrointestinal Conditions

Curcumin and curcumin--cyclodextrin (CD) inclusion complex were successfully encapsulated in almond gum/polyvinyl alcohol (PVA) nanofibers using electrospinning procedure. The release mechanisms and kinetics of encapsulated curcumin and curcumin-CD inclusion complex were evaluated in simulated gastrointestinal and simulated saliva conditions. The release data were fitted to zero order, Kopcha, Korsmeyer-Peppas, and Higuchi models to evaluate release mechanisms and kinetics. The controlled release of curcumin in simulated gastrointestinal and simulated saliva conditions showed that the nanofibers containing complex had the higher release in comparison of only curcumin at all time points. This can be related to the higher solubility of curcumin incorporated into the CD. The release profile of curcumin and its complex were similar. Release kinetics of curcumin and its complex in both simulated gastrointestinal and simulated saliva conditions followed a Fickian diffusion mechanism. The release data were well fitted with Kopcha, Korsmeyer-Peppas, and Higuchi models with R-2 values higher than 0.9176.