Effect of binder type and lubrication method on the binder efficacy for direct compression

The effect of different binders for direct compression on tablet critical quality attributes was investigated. Dicalcium phosphate, lactose and microcrystalline cellulose were used as fillers and combined with ten binders (10, 20 and 30% w/w). Binder properties were linked to tensile strength via partial least square analysis. Tablets containing VA64F and PH105 exhibited the highest tensile strength which was linked to their compaction properties (specific work of compaction, elasticity, cohesion index) and particle size. In contrast, S1500 and E15 exhibited the lowest tensile strength of all binders. Lubrication method influenced the tensile strength as lubricant sensitivity was observed to some extent for all binders. Tensile strength was significantly higher applying external compared to internal lubrication. Fast disintegration was observed for MCC (PH105 and PH200) and starch (S1500 and NMSt) grades, whereas HPC (KEXF and KEF) and E15 resulted in delayed disintegration. Wettability measurements, via determination of contact angle, correlated well with the disintegration behaviour of the binders and can therefore be used as an indicative measurement for tablet disintegration. This study revealed the effect of binder properties, filler type and lubrication method on tablet critical quality attributes. In addition, the potential of dry binder addition for direct compression was highlighted.