Patent ID: 7384661

Claim:
A method of electrostatically applying a powder material to a solid dosage form, the method comprising: applying a bias voltage to generate an electric field between a source of the powder material and the solid dosage form; applying an electrostatically charged powder material to the solid dosage form, the powder material being driven onto the solid dosage form by the interaction of the electric field with the charged powder material, and the presence of the charged powder material on the solid dosage form serving to build up an electric charge on the solid dosage form and thereby reduce the electric field generated by the bias voltage between the source of powder material and the solid dosage form, and continuing the application of the electrostatically charged powder material to the solid dosage form until the electric field between the source 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 is substantially terminated.