Polymeric Composite Films with Controlled Release of Natural Antioxidant Enoxil

The investigation was devoted to elaboration of effective carriers of biological active substrate based on natural tannins, namely, Enoxil. Several types of carriers based on silica or biocompatible natural polymers were synthesized and tested. Silica-containing composites have been prepared by impregnation of fumed silica with Enoxil and by sol-gel silica formation into the Enoxil solution. Polymeric films were composed by mixing of gelatin (Gel), chitosan (Chit), and 2-hydroxyethylmethacrylate (HEMA) in different proportions and compositions. Obtained materials were characterized using FTIR, ATR, and DSC. All materials were tested in vitro release and antibacterial static activity. The release rate of Enoxil from the carrier based on fumed silica A-300 was much higher compared with the liberation rate from the composites prepared by sol-gel method. The prolonged release of active substrate was obtained by use of the silica gel with phenolic groups as a carrier. Polymeric films based on gelatin/chitosan were found to show the highest swelling degree and reduced release. The composition with HEMA had more rigid structure, but the best carrier in this line samples was Gel/HEMA composite cross-linked with mixture of functional amino- and vinylsilane (Gel/HEMA/VA).