25A design of experiments (DOE) approach (2-level full factorial design) was used to investigate the effect of several formulation and process variables on the properties of fast disintegrating tablets comprising starch-based pellets and excipient granules and to optimize and validate the design space. The percentage of starch pellets (30-50% w/w), type of disintegrants (Ac-di-sol, Explotab, Polyplasdone), percentage of external disintegrant (4-8% w/w) and 30 compression force (5-15 kN) were the evaluated factors (24 runs + 9 centre points = 33 experiments), while tablet hardness, friability and disintegration time were the studied tablet properties (responses).Starch pellets were prepared by extrusion-spheronisation. Excipient granules containing microcrystalline cellulose, lactose, internal disintegrant (8%) and polyvinylpyrrolidone K-30
35(4%) were prepared by wet granulation. Pellets, granules (700-1000 µm) and external disintegrant were mixed and compressed into oblong tablets (17.1 mm long, 8.2 mm wide).Evaluation of the effects calculated from the DOE results showed that a lower concentration of starch pellets and higher compression force were required to yield tablets with a high hardness, a low friability (<1%) and short disintegration time (<3 min). Polyplasdone granules had the 40 lowest porosity and friability which was reflected in the DOE study, where the Polyplasdonecontaining tablets were harder, less friable and disintegrated faster compared to Ac-di-sol and Explotab-containing tablets. Monte carlo simulations at the optimal factor settings (30% starch pellets, 4% Polyplasdone and 10 kN compression force) indicated that a robust system was formed as the probability to exceed the limits was low for all responses. Validation of the design 45 3 space (at optimal settings) showed that the results predicted via the DOE models correlated well with the observed experimental data.
KEYWORDS