Preparation and characterisation of chitosan microspheres for antioxidant delivery

Encapsulation of olive leaf extract (OLE) in chitosan micropsheres was carried out by a spray-drying process. The interaction of polyphenolic compounds (PPCs) present in OLE within the polysaccharide matrix was studied using various physico-chemical techniques. Both the placebo and the OLE loaded microspheres were characterised by optical and scanning electron microscopy, particle size distribution analysis, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The particles obtained after spray-drying were found to be spherical and had uniform particle size distribution patterns. FTIR and DSC indicate that there are interactions of polyphenolic compounds in OLE with the chitosan matrix. Further studies on encapsulation of OLE and its activity were analysed after the total hydrolysis of OLE loaded chitosan microspheres. The released polyphenolic compounds in OLE were estimated to confirm the activity of OLE loaded into the microspheres. The loading percent of polyphenolic compounds through encapsulation of OLE achieved was 27%.