Film coatings applied to tablets and capsules make them easier to swallow by imparting a smoother surface and masking unpleasant taste or odor. Coatings also help retain the tablet’s shape, enhance shelf-life and even control the location and timing of drug release.
Most tablet coatings are solid suspensions or solutions which may contain various ingredients such as natural or synthetic resins, polymers, gums, plasticizers, fillers, pigments and flavors. Proper mixing is critical in achieving the desired film properties, clarity, color, particle size distribution and viscosity.
This bulletin discusses two efficient techniques for processing tablet coating formulations: high-speed sub-surface powder injection and ultra-high shear mixing.