Study on chitosan-calcium pectin microsphere preparation and in vitro swelling and release properties

Bovine serum albumin (BSA) loaded chitosan-calcium pectin microspheres were prepared by ionotropic gelation/polyelectrolyte complexation. Microspheres were characterized for encapsulation efficiency (EE) , loading capacity (LC) , in vitro swelling ratio (SR) and release rate (RR) in different environments simulating the gastrointestinal tract. The effects of concentration of pectin, calcium chloride and chitosan on the quality of microspheres were studied. The results showed that the optimal formulation was as follows:7% (w/v) pectin solution, 3% (w/v) calcium chloride solution, pH 5.5 calcium chloride-chitosan crosslinking solution, 0.50% (w/v) chitosan solution and 5% (w/v) BSA solution. Correspondingly, the encapsulation efficiency and loading capacity of chitosan-calcium pectin microspheres were 89.68% and 32.13%, respectively. Release time was significantly prolonged and sustained -release effect was effectively improved. Thus the microspheres could efficiently encapsulate BSA and had potential for intestinal delivery through the oral administration.