The invention relates to an apparatus for the preparation and sterilization of a viscous fluid (10) containing a temperature sensitive compound (11) diluted into a viscous matrix (12), characterized in that it comprises: - a heat treatment unit (15), fed with the viscous matrix (12), wherein the viscous matrix (12) is sterilized, - a mixing unit (17), fed with the sterilized viscous matrix (12) and the sterile temperature sensitive compound (11), wherein the temperature sensitive compound (11) is incorporated into the sterilized viscous matrix (12) to form the viscous fluid (10).
