Palatability and patient acceptability are critical attributes of dispersible tablet formulation. Co-processed excipients could provide improved organoleptic profile due to rational choice of excipients and manufacturing techniques. The aim of this study was to identify the most suitable co-processed excipient to use within directly compressible dispersible tablet formulations. Nine excipients, selected based on successful manufacturability, were investigated in a randomised, preference and acceptability testing in 24 healthy adult volunteers. Excipients were classified in order of preference as follows (from most preferred): SmartEx QD100 > F-Melt Type C > F-Melt Type M > MicroceLac > Ludiflash > CombiLac > Pharmaburst 500 > Avicel HFE-102 > Avicel PH-102. Broad differences were identified in terms of acceptability, with SmartEx QD100 being 'very acceptable', F-Melt Type C, F-Melt Type M and MicroceLac being 'acceptable', Ludiflash, CombiLac and Pharmaburst 500 being 'neutral' and Avicel products being 'very unacceptable' based on ratings using five-point hedonic scales. Organoleptic differences were ascribed to different composition and physical properties of excipients, resulting in dissimilar taste and mouth-feel. Excipients with particle size in water larger than 200-250 μm were considered poorly acceptable, which supports the use of this value as a threshold for maximum particle size of dispersible formulation. The most promising co-processed excipients for directly compressible dispersible tablets were successfully identified.
Keywords: co-processed excipients; dispersible tablets; palatability; patient acceptability; taste.