EXPLORING THE EFFECT OF PROCESS VARIABLE IN PELLETS COATING BY WURSTER FLUID BED COATER

Abstract

The aim of the present investigation was to study the effect of various process parameters for enteric coating of pellets by fluid bed processor in wurster coating process, as well as the optimization of such parameters during scale-up process. Bottom spray technique is one of the most preferred approaches for coating of multi-unit pellets and mini-tablets. Several process related factors influence the performance of formulation; and thorough knowledge about these factors and their control during process scale-up helps smooth technology transfer as well as promotes reduction of batch failure. Preliminary, several batches were formulated by varying different factors like seal coating thickness, percentage of enteric coating, ratio of coating solution, spray rate, humidity, temperature, etc. to understand the effect of such factors at a glance. Later on, critical factors like inlet humidity, chamber temperature and spray rate were identified as significant parameters affecting the coating process. Critical factors were further optimized by applying 23 full factorial design, whereby these factors were studied at two levels and other factors were fixed at single level as per preliminary batches. Result indicated that all the independent parameters have positive effect and interaction of the parameters have not significant effect or negative effect on the T10, T15, T20 and impurity. Study revealed that spray rate and temperature have positive effect on the dissolution and RH has positive effect on the total impurity (RS). Optimized batch was obtained scientifically by overlay plot by response surface methodology for various factors. Scale-up batch was also formulated as per optimized batch, and no significant difference in product performance was observed, which indicates that appropriate selection of critical factors and their control helps in smooth process scale-up.