Synthesis and Performance of PLA/TCP Microspheres

Polylactic acid/hydroxyapatite(PLA/TCP)composite microspheres were prepared through solvent evaporation method by choosing PLA as carrier and TCP as core materials.On the basis of ensuring the quality of produced particles,the concentration of emulsifier and other factors were adjusted in a certain range to control the average particle sizes of microspheres after the confirmable factors were fixed.Single factor experiment results showed that:there were four factors significantly effecting on the performance of the microspheres,concentration of PLA and emulsifier,stir speed and oil-water ratio.The best craft to obtain PLA/TCP microspheres with the diameters of about 200 μm was found through orthogonal-designed experiment,stir speed was 600 r·min-1,concentration of PLA was 0.07 g·mL-1,concentration of PVA was 0.005 g·mL-1 and oil-water ratio was 10∶50(mL/mL).The distribution of microspheres was more uniform with the faster stir speed was found by analyzing the data of laser particle size analyzer;SEM showed that microspheres were spherical and with non-adhesion;the rules and mechanism of degradation of PLA/TCP microspheres was studied by detecting PH changes in phosphate buffer;the good drug-releasing properties was found by researching drug-releasing rate of PLA/TCP microspheres.