Tabletability Enhancement of Acetaminophen Coated with a Nanocellulose Suspension using a Fluidized Bed

Fluidized bed coating was investigated as a method to coat aqueous suspensions of nanocellulose onto acetaminophen (APAP) for the purpose of tabletability enhancement. Effects of suspension concentration and fluidized bed processing conditions were evaluated. Nanocellulose coatings of up to 2.0% w/w were achieved. This study found that the nanocellulose coating significantly improved the tabletability of APAP. A 2.0% w/w coating increased tablet tensile strength by nearly 200%. With respect to tablet formulation, it was found that APAP coated with 2.0% w/w nanocellulose allowed a 60% reduction in filler to produce tablets acceptable for manufacturing compared to APAP without nanocellulose. The effectiveness of fluidized bed coating was also compared to a twin-screw extrusion process which was previously used to coat nanocellulose onto APAP. It was concluded that process conditions and the process method had no effect on the extent of tabletability enhancement provided by nanocellulose. Improvement to tabletability was only dependent on the concentration of nanocellulose coated. Fluidized bed coating may be more advantageous than twin-screw processing due to the inherent ability of the former to better control liquid addition and removal. Accordingly, fluidized bed coating was able to achieve a higher coating concentration than the twin-screw process. Overall, the use of small amounts of nanocellulose to substantially improve tabletability of APAP and to reduce the need for filler excipients is evident.