Antibiotic delivery based on poly(lactic- co -glycolic) acid and natural polymers: a biocomposite strategy

Polymer controlled release systems are being widely studied as new therapeutic options. The main objectives of these systems are active principle levels control, doses number optimization, secondary effects reduction and patient acceptance. The aim of this study was to design systems for tilmicosin and clarithromycin delivery. To achieve this goal, synthetic and natural polymers, combined with drug saturated suspensions, were evaluated to improve encapsulation efficiencies and release rates of the active principles. Firstly, two systems were studied: poly(lactic- co -glycolic) acid microparticles and biopolymer beads. Depending on the antibiotic used, the microparticles reached encapsulation efficiencies (EE) of 30–90%. Depending on the type of antibiotic and synthesis factors, beads showed EE of 0–40%. The drug release rates were lower for microparticles than those for beads. On the other hand, the inclusion of microparticles into beads was explored as an option for the preparation of biocomposite systems. The release rate of tilmicosin was diminished while that of clarithromycin was not improved. The investigated systems can be an interesting approach for new therapeutic options in the fields of animal and human health. Graphical abstract