Optimization of Tablet Coating

Although being one of the earliest pharmaceutical unit operations, tablet coating is still extensively employed in pharmaceutical industries. The application ranges from merely masking the bitter taste and odour of active pharmaceutical ingredients to achieving site-specific and rate-specific drug release. The widespread applicability and high expectations by varied coating techniques have required implication of greater efforts for developing controllable and reproducible coating processes. Improvement in substrate movement, transport of energy and air and spraying techniques have been targeted to achieve homogeneous coating layer, enhanced drying efficiency, and an overall high-end product. As per regulatory guidelines, designing high-end product by controlling, monitoring and designing the manufacturing process (quality by design), the implication of modelling approaches and process analytical techniques has engrossed superior attention during recent decades. Implementation of the quality by design approach helps in better understanding and controlling the processing variables and their interdependencies. The quality by design approach is based on establishment of the quality target product profile. It involves designing the experiments based on the identified critical processing parameters and critical material attributes. Furthermore, implementation of modelling approaches and process analytical tool facilitates manufacturing of a product with a consistent quality.