the present invention provides a composition which comprises a polymer or polymer solution that forms a gel under controlled parameters and a ceramic matrix , the composition being fluid under non - physiological conditions and non fluid under physiological conditions . polymers may be resorbable or non - resorbable , natural or synthetic and the solution aqueous or non - aqueous . preferred polymers are poly saccharides , polyamides or polyamino acids , however any polymer or polymer solution that is biologically compatible and that is fluid under nonphysiological conditions and increases in viscosity under physiological conditions is suitable .