| abstract |
Capsules, for example for the delivery of pharmaceuticals, are produced from two films ( 18 ) of a water-soluble polymeric material, by deforming the films to form a multiplicity of recesses, and filling the recesses, using two adjacent rotary dies ( 14, 15; 42 ) with recesses ( 16 ) into which the films ( 18 ) are deformed. The dies ( 14, 15; 42 ) act as electrodes for welding the films together by dielectric welding to form filled capsules ( 30 ). The capsules ( 30 ) can be separated from the resulting web either by coating at least one of the dies ( 14 ) with an electrical insulator ( 21 ), or by transferring the web from the dies ( 14, 15; 42 ) to a second pair of dies which cut the capsules ( 30 ) free. The polymeric material may be gelatin, or a water-soluble cellulose derivative such as hydroxypropyl methyl cellulose, and may also contain a plasticiser. |