Study on the Slow-Release Mometasone Furoate Injection of PLGA for the Treatment of Knee Arthritis

Purpose: The purpose of this study is to develop a new PLGA based formulation for microspheres, which aims to release mometasone furoate for one month, so as to improve compliance. Methods: The microspheres containing mometasone furoate were prepared by oil in water emulsion and solvent evaporation. The microspheres were characterized by surface morphology, shape, size and encapsulation efficiency. The release in vitro was studied in 37°C phosphate buffer, and in vivo, pharmacodynamics and preliminary safety evaluation were conducted in male Sprague Dawley rats. Results: The morphology results showed that the microspheres have a smooth surface, spherical shape and an average diameter of 2.320-5.679μm. The encapsulation efficiency of the microspheres loaded with mometasone furoate was in the range of 53.1% to 95.2%, and the encapsulation efficiency of the microspheres could be greatly affected by the proportion of oil phase to the water phase and other formulation parameters. In vitro release kinetics revealed that drug release from microspheres was through non-Fick's diffusion and PLGA polymer erosion. Pharmacokinetic data showed that the initial release of microspheres was small and then sustained. The results of the pharmacodynamics study fully proved the long-term effectiveness of mometasone furoate microspheres. The results of in vivo safety evaluation showed that the preparation system possessed good in vivo safety. Conclusion: This study shows that the microspheres prepared in this study have sufficient ability to stable drug release at least for 35 days, with good efficacy and high safety. In addition, mometasone furoate can be used as a potential candidate drug for 35 days long-term injection.