Behaviour of an injectable calcium phosphate cement with added tetracycline.pdf

International Journal of Pharmaceutics 274 (2004) 261–268 Behaviour of an injectable calcium phosphate cement with added tetracycline A. Ratier a , M. Freche b,? , J.L. Lacout b , F. Rodriguez a a Laboratoire de Pharmacie Galénique, GEFSoD EA 2631, Faculté des Sciences Pharmaceutiques, 35 chemin des Mara??chers, 31062 Toulouse Cedex, France b CIRIMAT Physico-Chimie des Phosphates, UMR CNRS 5085, ENSIACET, 118 route de Narbonne, 31077 Toulouse Cedex, France Received 1 August 2003; received in revised form 8 January 2004; accepted 19 January 2004 Abstract A calcium phosphate cement containing an antibiotic can be used for filling bone defects and to ensure local antibiotherapy. A calcium phosphate cement (already marketed under the name of Cementek ? ) can become injectable thanks to the addition of silicone. For dental applications, the behaviour of this injectable cement with added tetracycline was investigated. The tetracycline hydrochloride does not allow maturation of the cement: the tetracycline has to be treated with a calcium sulphate solution. The treated tetracycline (TTC) allowed maturation of the cement towards hydroxyapatite. But the setting time was longer and the mechanical properties decreased. Study in a continuous flow cell showed that the tetracycline is released in a continuous manner: thus, after 6 days, 60% of the antibiotic was released into the surrounding medium. ? 2004 Elsevier B.V. All rights reserved. Keywords: Calcium phosphate; Cement; Injectable; Tetracycline 1. Introduction Calcium phosphate cements are used in surgery or dentistry for filling bone defects (Fukase et al., 1990; Ogilvie et al., 1987). The “in vivo” use of such bioma- terials requires preventive antibiotic therapy to avoid the development of postoperative infections. This is achieved either by daily systemic administration (oral or injection) or by “in situ” application. We hope to propose local treatment released “in situ” from the ce- ment. The introduction of active in