Luteolin/dextran-FITC fluorescent microspheres produced by supercritical assisted atomization

Supercritical Assisted Atomization was used to produce a complex particulate system, consisting of a polysaccharide (Dextran, DEX) loaded with a fluorescent agent (Fluorescein isothiocyanate, FITC) and a poorly water soluble compound (Luteolin, LUT). Different LUT/(DEX + FITC) weight ratios and different concentrations were investigated to develop microparticles that can act as an imaging agent and as a drug delivery carrier. SAA produced spherical, well-separated and amorphous particles. Analytical studies revealed that LUT was uniformly dispersed in DEX matrix and specific interactions appeared between LUT and DEX. LUT loading efficiencies reached 100% and dissolution tests in a phosphate-buffered saline solution were up to 18 times faster compared to the physical mixture, due to an efficient dispersion of LUT in DEX matrix and to the formation of hydrogen bonds between LUT and DEX. All results confirmed that the presence of FITC in SAA coprecipitates did not influence particle size, morphology and LUT dissolution rate.