Patent ID: 7836606

Claim:
A process for producing a dosage of a sterile freeze-dried product in the form of pellets in a container, the amount of active ingredient of which is equal to a predetermined amount or exceeds such predetermined amount by less than 10% by weight, which comprises the steps of forming droplets by passing a solution of the product through frequency assisted nozzles and passing said droplets to an isolated tunnel supplied with a flow of cryogenic gas and allowing said droplets to fall through a counter-current flow of said cryogenic gas in said isolated tunnel to form pellets of a size which, when freeze dried, have a particle size distribution of 500 μm<d 50 <1500 μm, said tunnel being long enough to provide a residence time sufficient for the cooling and freezing of the falling droplets, freeze-drying the pellets to form freeze-dried pellets having a particle size distribution of 500 μm<d 50 <1500 μm, storing and homogenizing the freeze-dried pellets, assaying the freeze dried pellets while they are being stored and homogenized to determine the concentration of active ingredient in said freeze dried pellets, determining the amount of the homogenized freeze dried pellets required to provide a predetermined amount of the active ingredient and loading the freeze-dried and homogenized pellets into said container in an amount that is at least equal to and less than 10% by weight in excess of the determined amount.