In vitro release of tetracycline hydrochloride from alpha-TCP cement / 生物医学工程学杂志

ABSTRACT

Drug release from alpha-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 alpha-TCP. In vitro drug release study showed that TTCH release could sustain over 1200 h, 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 would changed with the variety of the antibiotic content of cement pellets, as a result of TTCH adsorption and bonding on calcium phosphates. The first mechanism was predominantly for low concentration 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.