Conversion of indomethacin nanosuspensions into solid dosage forms via fluid bed granulation and compaction

Preparation of pharmaceutical nanosuspensions is a popular technique to increase the dissolution velocity of poorly water-soluble drugs. Subsequent drying into a compaction-ready powder or granule is a critical process due to possible adverse solid characteristics and the risk of growth of nanoparticles. This work evaluated the drying of nanosuspensions via fluid bed granulation with focus on the binder selection and used concentrations, as well as the parameters spray rate and atomization pressure. Design of experiments was used to identify significant parameters. Indomethacin nanosuspensions were prepared by wet media milling and dried on a carrier consisting of lactose, microcrystalline cellulose, and crospovidone with and without additional binder during granulation. Resulting granules were compacted into tablets and their in vitro dissolution performances were characterized. A higher content of binder PVP and a higher spray rate led to less growth of resuspended nanoparticles. Finally, indomethacin nanoparticle tablets showed a superior dissolution performance in contrast to raw indomethacin tablets.