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
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.