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.