α-Tocopherol-loaded Ca-pectinate microcapsules: Optimization, in vitro release, and bioavailability

We used response surface methodology to optimize microcapsule preparation conditions, including the ratio of pectin:α-tocopherol (TP) (X1), emulsifier concentration (X2), and CaCl2 concentration (X3) for maximal entrapment efficiency (EE) of TP-loaded Ca-pectinate microcapsules. The values of X1, X2, and X3, optimized for maximal EE were a ratio of 9.7:6.3, and 1.33% and 5.09%, respectively. The experimental results obtained from the optimum formulation agreed with the predicted results, indicating the usefulness of models for EE. TP release from the Ca-pectinate microcapsules prepared according to the optimized conditions was slow and incomplete in simulated gastric fluid, whereas it was relatively rapid and considerably sustained in simulated intestinal fluid. An in vivo release study revealed that physical entrapment of TP within Ca-pectinate microcapsules can be a good technique to demonstrate the sustained release pattern of TP and to improve the bioavailability for TP following oral administration.