Acceleration of heat transfer in vial freeze-drying of pharmaceuticals. I: Corrugated aluminium quilt

The medium offering the greatest resistance to heat transfer from the freeze-dryer shelf to the moving and subliming interface within the product is the space between the flat shelf top and the concave vial bottom. The resistance to heat transfer can be greatly reduced by improving the thermal conductivity of this intervening space. Several heat transfer augmentation devices, which fill this gap, are described. The devices are inexpensive and easy to use. Experimental data show that the resistance of the intervening space is reduced appreciably and the drying time is greatly reduced.