3rd Year Notes

Rationale for coating a solid dosage form?
Therapy
ª To minimise irritation of the oesophagus and stomach.
ª Minimise inactivation in the stomach.
ª Improve drug effectiveness.
ª Improve patient compliance e.g. easier to swallow, masks unpleasant taste.
Technology
ª Minimise dust formation and contamination with respect to tablets.
ª Masks batch differences in the appearance of raw materials.
ª Facilitates their handling on high speed automated filling and packaging
equipment.
ª Improves drug stability e.g. Protection of active ingredient from environment such
as sunlight, moisture.
Marketing
ª Aid sales appeal as improved appearance and acceptability with respect to gloss
and colouration.
ª Mask unpleasant taste.
ª Improve product identity.
Main Coating Processes
Î Film Coating
Î Sugar coating
Î Press coating
Sugar coating
¾ Compressed tablets may be coated with colored or uncolored sugar layer.
¾ The coating is water soluble and quickly dissolves after swallowing.
¾ The sugarcoat protects the enclosed drug from the environment and provides a barrier to
objectionable taste or order.
¾ The sugar coat also enhances the appearance of the compressed tablet and permit
imprinting manufacturing’s information.
¾ Sugar coating provides a combination of insulation, taste masking, smoothing the tablet
core, coloring and modified release.
¾ The disadvantages of sugar coating are the time and expertise required in the coating
process and thus increases size, weight and shipping costs.
Description of tablets: Smooth, rounded and polished to a high gloss.