盐酸四环素/α-TCP骨水泥载药体系的体外释放研究

In Vtro Release of Tetracycline Hydrochloride from α-TCP Cement

对盐酸四环素 /磷酸钙骨水泥药物释放体系进行了体外释放研究。 XRD分析结果表明 ,一定含量的盐酸四环素的存在不会影响 α- TCP的水化。在体外释放实验中 ,各种药物含量的载药体系均表现出了良好的缓释性能 ,持续释放时间超过 12 0 0 h;由于盐酸四环素同磷酸钙的吸附与结合 ,当药物在体系中的含量发生改变时 ,释放控制机理发生改变。当抗生素在固相中含量较大时 ,药物释放速率以扩散控制为主 ,药物释放量满足时间平方根关系 ;当药物含量较低时 ,在释放前期 ,药物释放速率仍然以扩散控制为主 ;释放后期 。

Drug release fromα TCP cement containing tetracycline hydrochloride (TTCH) was studied in vitro. Results from X ray diffraction study indicated that TTCH did not prevent the hydration of α TCP. In vitro drug release study showed that TTCH release could sustain over 1200h, and the release was controlled by two mechanisms: (1) diffusion of free TTCH molecules through the porous cement (square root of time kinetics); (2) dissociation of TTCH from the apatite TTCH complex (zero order kinetics). The mechanism controlling release wold changed with the variety of the antibiotic content of cement pelletsas a, result of TTCH adsorption and bonding on calcium phosphates. The first mechanism was predominantly for low concentriation system TTCH loaded apatite cement systems at the initial release period, and for high concentration TTCH loaded apatite cement systems. As for low concentration TTCH loaded apatite cement systems at later release stage, drug release was controlled by the coupling of the two mechanisms.