Prilling apparatus

A prilling apparatus for prilling pharmaceuticals and the like, comprising:

• means for supplying a melted mixture of a pharmaceutical and a vehicle at a preselected pressure and at a temperature less than the decomposition temperature of the pharmaceutical and wherein the vehicle is a solid at normal room temperature;
• gun means including
• a. a melt chamber connected to said supply means for receiving said melt mixture,
• b. a substantially downwardly directed nozzle communication with said chamber,
• c. a valve member and biasing means normally urging said valve member to a closed condition blocking said communication between said chamber and nozzle to prevent melt material flow out of said nozzle,
• d. shift means actuable for shifting said valve member to an open condition permitting said pressurized melt mixture to escape the gun through said nozzle;
• means for generating a train of electrical pulses of preselected frequency and width;
• transducer means responsive to said pulse train and coupled to said shift means for periodically opening said valve means at said frequency with a preselected duration controlled by said pulse width and therewith ejecting from said nozzle a series of spaced droplets of melt mixture at said frequency and of size controlled by said pulse width;
• container means extending downward below said nozzle and surrounding a gravity drop path for the droplets;
• and
• fluid means in said container for congealing said droplets as they fall along said path to form same into substantially spherical prills.