Preparation and characterization of three types of cefquinome-loaded microspheres

The polymers of poly (lactic-co-glycolic acid), gelatin, and ethyl cellulose were used to control the microscopic structure of microspheres prepared by spray drying. We investigated controlled release by varying material concentrations, sprayer inlet temperatures and air velocities, and optimized process parameters of yield, particle size, and distribution. Three types of polymeric microspheres with a mean particle size range of 13–25 µm were loaded with cefquinome and characterized. In vitro drug release studies determined that microspheres were the most suitable structures for controlling release due to their high entrapment capacities and release times greater than 24 h.