Development of a single-jet electrospray method for producing quercetin-loaded poly (lactic-co-glycolic acid) microspheres with prolonged-release patterns

Quercetin has been reported to possess unique biological effects. Here, we describe an electrospraying method for the preparation of poly (lactic-co-glycolic acid) (PLGA) microspheres, which serve as a platform for the long-term release of quercetin. Optimal microspheres had a narrow size distribution (1-4 mu m), as determined by scanning electron microscopy. Quercetin was successfully incorporated into the PLGA matrix in the amorphous or molecularly dispersed state, as evidenced by XRD and DSC spectra. The FTIR spectra revealed no chemical interaction between quercetin and PLGA. The drug encapsulation efficiency and loading capacity of microspheres were 81.84 +/- 1.60% and 7.77 +/- 0.15%, respectively. Importantly, quercetin exhibited a prolonged-release pattern for 30 days in vitro with little evidence of burst release. Finally, cytotoxicity study revealed that the PLGA microspheres exhibited no toxic effects when treated to INS-1 cells. The study indicates that the developed electrospray method may be suitable for the preparation of quercetin-loaded PLGA microspheres.