Study on the Efficiency of Hard Gelatin Capsules Coating in a Spouted Bed

Abstract

The aim of this work was to study the process of capsules coating in a lab-scale spouted bed. A conventional spouted bed (CSB) with 9.5 cm column diameter and 60° conical base was used in the experiments. The spouting fluid dynamics of capsules with different sizes were determined. In the equipment used only capsules size 03 (outer diameter: 5.82 cm; length: 15.9 mm) presented stable spouting. The effect of capsules load in the column, coating suspension viscosity, and coating time on the coating efficiency were studied in a factorial experimental design. Typical efficiencies for the process were found to be in the range of 69.54–84.88%. The efficiencies increased with bed load at 1% significance level, but were not affected by coating time and suspension viscosity. CBS is a promising method for the HGC coating that eliminates preliminary sealing steps.

Keywords:

• Fluid dynamics
• Stability
• Methacrylic polymer
• Suspension viscosity

ACKNOWLEDGMENT

Financial support from FAPESP (99/10183-6 and 02/00291-0) is gratefully acknowledged.

Notes

*Significant at 1% level.