Compactibility of the microcrystalline cellulose102-calcium phosphate dihydrate system

This paper reports the effect of the formula composition on the compactibility of tablets made of mixtures of different proportions of microcrystalline cellulose type 102 (CM102) and calcium phosphate dihydrate (FC). Compactibility curves (tablet hardness [D]-compaction pressure [Pc]) of 11 different mixtures of the CM102-FC system were determined in a range of compaction pressure up to 980 Mpa, using hydraulic presses. The compactibility of each different powder's mixture was defined through the maximal tablet hardness reached (Dmax) and the slope (n) and the intercept (I) of the curves, according to In (-ln (1-D/Dmax)) = n * ln Pc + I. The experimentally determined Dmax values increased linearly with an increasing proportion of CM102 in the mixtures, and were found ranging between 6.6 and 11.2 Mpa. The data showed a small deviation from linearity (smaller tablet hardnesses than that expected) at different compaction pressures under the pressure needed to reach the maximal tablet hardness of the systems. These results are different from that obtained with microcrystalline cellulose type 101 and FC, which showed a maximal tablet hardness by about 80% of CM101 in the mixtures.