An apparatus for the preparation and sterilization of a viscous fluid containing a temperature sensitive compound diluted into a viscous matrix, characterized in that it includes: a heat treatment unit, fed with the viscous matrix, wherein the viscous matrix is sterilized, a mixing unit, fed with the sterilized viscous matrix and the sterile temperature sensitive compound, wherein the temperature sensitive compound is incorporated into the sterilized viscous matrix to form the viscous fluid.
