Evaluation of the tablet coating by the conventional spouted-bed process.
The purpose of this paper was to present an analysis of the tablet coating by the conventional spouted-bed process. To analyze the equipment performance, the rate of increase of the tablets mass, K1, and the adhesion coefficient eta were determined as a function of the feed flow rate of coating suspension Ws; of the Reynolds number Rep; of the flow rate of atomizing gas Wat, and of the cone base angle gamma. To analyze the product quality, the uniformity of coating mass deposition onto the tablet's surface was used. Three different procedures for description of kinetics growth, weighing method, image analysis, and measurements with a micrometer were used to verify the validity of the commonly used weighing method. Comparison between experimental results of kinetics growth with estimates obtained by a literature model was also performed. A tendency toward an increase in K1 and in eta with the feeding flow rate of coating suspension Ws was detected. The weighing method can be used for the process analysis. The kinetics of growth can be described by the growth model used. The variable that produce more pronounced effect on K1 and eta was the feed flow rate of coating suspension, the weighing method describes very well the increase of particle diameter with coating time, the growth model can be used for the describe the kinetics of growth during the coating operation, and the coating does not deposit uniformly onto the tablet's surface.
Silva
G D
GD
Laboratory of Industrial Physics, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14040-903.
Publio
M C
MC
Oliveira
W P
WP
D002626:Chemistry, Pharmaceutical / Q000379:methods*; D013607:Tablets; D013678:Technology, Pharmaceutical
D013607:Tablets