PART I - PROCESS ANALYSIS AND MATHEMATICAL MODELING OF AQUEOUS TABLET FILM COATING IN PRODUCTION SCALE EQUIPMENT; PART II - DESIGN AND EVALUATION OF TABLET SUGAR COATINGS FOR AUTOMATED SPRAY APPLICATION
Abstract
In the first part of this study a mathematical model for an aqueous film coating process in a production size coating pan was developed which would allow the effects of process variables and their interactions with the coating process to be identified and subsequently predicted with mathematical certainty. Because excess water accumulation in the tablet bed can be undesirable and effective water removal is critical to an efficient process, the dependent varaible selected in the study was water removal efficiency. The independent variables considered in the study were coating solution spray rate, inlet air temperature, exhaust airflow, pan rotational speed and total tablet surface area. In order to establish the appropriate operating conditions for the coating pan it was necessary to evaluate the mixing action of the baffled pan and the various spray gun configurations available for use in the unit. This included the study of spray patterns and determination of the optimal spray rates for uniform tablet coverage. Tablet surface area was also determined to be a critical parameter which had a significant effect on the drying air flowing through the tablet bed. The results from the studies indicate that the model developed could predict water removal efficiency with a satisfactory degree of assurance. Graphical analysis indicated interactions between pan speed and air temperature, and pan speed and airflow. In the second part of this research, a standard production sugar coating suspension which had been applied manually was modified to allow for spray application in an automated tablet sugar coating process. Ingredients which may have contributed to microbiological growth were eliminated. A mathematical model was developed which predicted the viscosity of the subcoat suspensions containing different concentrations of selected coating ingredients. A subcoat suspension formula was selected and the effect of the addition of various synthetic polymers on the strength and disintegration rate of coated tablets was evaluated. The results indicated that the new subcoat suspension containing synthetic polymers provided a sugar coat that was as physically strong as the standard production formula but disintegrated more rapidly from the tablet.
Degree
Ph.D.
Subject Area
Pharmaceuticals
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.