Electrostatic application of powder material to solid dosage forms in an electric field.

摘要

A method of electrostatically applying a powder material to a solid dosage form comprises the following steps: applying a bias voltage to generate an electric field between a source ( 1 ) of the powder material and the solid dosage form ( 5 ); applying an electrostatically charged powder material to the solid dosage form ( 5 ), the powder material being driven onto the solid dosage form ( 5 ) by the interaction of the electric field with the charged powder material, an the presence of the charged powder material on the solid dosage form serving to build up an electric charge on the solid dosage form ( 5 ) and thereby reduce the electric field generated by the bias voltage between the source ( 1 ) of powder material and the solid dosage form ( 5 ), and continuing the application of the electrostatically charged powder material to the solid dosage form ( 5 ) until the electric field between the source ( 1 ) of powder material and the solid dosage form is so small that the driving of the powder material by the electric field onto the solid dosage form ( 5 ) is substantially terminated.