Synergistic Sustained Drug-Release System Based on Immobilized L. Phytoextract into Layered Double Hydroxide Covered by Biocompatible Hydrogel.

This work focuses on the synergetic effect obtained by immobilization of L. phytoextract in layered double hydroxides (LDHs) matrixes and their subsequent encapsulation into biocompatible hydrogels (HG). In this respect, the LDHs were used as hosts for the immobilization of the phytoextract by a reconstruction method, after which the LDHs were embedded into biocompatible hydrogel (HG) matrixes, based on polyethylene glycol diacrylate (PEGDA), by a radical polymerization reaction. The resulted biocompatible hydrogel composites were characterized by modern methods, while the swelling and rheology measurements revealed that the HG composites steadily improved as the content of phytoextract immobilized on LDHs (LDHs) increased. The following in vitro sustained release of the phytoextract was highlighted by measurements at pH 6.8, in which case the composite HGs with LDHs presented an improved release behavior over the LDHs, thus, underlining the synergistic effect of PEGDA network and LDH particles on the slow-release behavior. The kinetic models used in the release from composite HGs clearly indicate that the release is diffusion controlled in all the cases. The final composite HGs described here may find applications in the pharmaceutical field as devices for the controlled release of drugs.