Biopolymer matrix systems for incorporation of biologically active substances

S. Dyankova, A. Solak
Abstract. A number of biopolymers have a potential to be used as a basis for producing films, coatings and therapeutic systems with application in medicine, pharmacy and food industry. The objective of the present work was to obtain monopolymer and composite matrices which can be used as carriers of biologically active substances. Protein (collagen, gelatin, soy protein) and polysaccharide (sodium alginate, highmethoxyl pectin, carrageenan and carboxymethylcellulose) hydrocolloids were investigated and a method for producing monopolymer and composite films was developed. The obtained materials were characterized by their physicochemical and mechanical properties; their behavior at different pH values and in media simulating the conditions in the gastrointestinal tract. The protein films showed lower moisture content and absorbed less water compared to the polysaccharide films. It was found that films prepared from collagen dispersions were the most resistant at different pH and in simulated gastric and intestinal juice. The polysaccharide films dissolved under the studied conditions except for the alginates which kept their wholeness in acidic medium and in simulated gastric juice, but degraded in intestinal juice. The combination of two biopolymers – protein-polysaccharide or polysaccharide-polysaccharide improved considerably the mechanical properties of the films. All composite films also showed significant differences in the dissolution profile compared to the individual biopolymer films.