The Polymers Forming the Covers of Calcium Carbonate Cores. Influence of Their Rheological Characteristics on the Structure and Function of Oral Delivery Systems

The rheological characteristics of polymer mixtures used for making multilayer polyelectrolyte covers on carbonate cores in drug delivery systems were studied. The cover structure is primarily determined by the first polymer layer, its excess charge, concentration, and ionic surrounding. The correctness of the interpretation of the viscometric data is confirmed by scanning electron microscopic examination of carbonate cores with polymer covers formed under different conditions. The molecular mass of the polymers influences the release profiles of a therapeutic protein encapsulated in delivery systems into liquids simulating gastrointestinal media.