Preparation of chitosan-TPP microspheres as resveratrol carriers.

Resveratrol (3,4',5-trihydroxy-trans-stilbene)-loaded chitosan-sodium tripolyphosphate (TPP) microspheres using high (310 to 375 kDa) and medium (190 to 310 kDa) molecular weight chitosan and TPP in varying concentrations were produced to improve resveratrol bioavailability. A 450 µm nozzle encapsulator was used to produce the microspheres. The mean microsphere particle size was between 160 and 206 µm, and exhibited a narrower size distribution as the TPP solution concentration increased. The encapsulation efficiency increased from 94% to 99% with a decrease in chitosan concentration from 1% to 0.5% and a decrease in crystallinity of the microspheres. FTIR data showed a polyelectrolyte interaction between chitosan and TPP. X-ray diffraction patterns were matched up with DSC and FTIR, which shows decrease of crystallinity and enhancement of hydrogen bonding with TPP concentration. An increase in the concentration of TPP solution from 1% to 3% led to a lower initial burst of resveratrol release. These results suggest that chitosan-TPP microspheres could be used as a potential delivery system to control the release of resveratrol.