Effect of Binder Type and Binder Level on the Properties of Agglomerates Containing Lactose and Dibasic Calcium Phosphate Dihydrate
The authors studied the effect of the combination of binders on the flow and compressibility characteristics of the agglomerates of binary combination of lactose and dibasic calcium phosphate dihydrate.
Figure 1, (All figures are courtesy of the authors.)
The results of regression analysis (see Table V) indicate that silicon dioxide had a significant effect on the angle of repose
(Y1) and compressibility index (Y2) of the agglomerates. Silicon dioxide had the lowest values of the coefficients in the regressed equations for the angle
of repose and Carr's index. The high-value coefficients for silicon dioxide in equations for CSB (Y3) and CSP (Y4) indicate that using silicon dioxide increases the hardness of the tablets more than using both HPMC and PEG. The role of
silicon dioxide in increasing the hardness of tablets also been has appreciated by Linden et. al (3). The combination of starch,
guar gum and silicon dioxide was thus vital to achieving the desirable attributes for the tablets.
Figure 2, (All figures are courtesy of the authors.)
Figure 1 indicates that for obtaining the lower values of angle of repose, the amount of all three components should be kept
low. At higher amounts of HPMC and silicon dioxide, the interaction between the two components becomes more prominent, and
the graph loses its linearity. Nevertheless the angle of repose values are <25 for all combinations of HPMC and silicon dioxide
when PEG is absent.
Figure 3, (All figures are courtesy of the authors.)
Figure 2 indicates that a high level of HPMC and a low level of silicon dioxide gives lower values of Carr's index and vice versa. The interaction between the three components plays a major role in determining the value of compressibility index, as indicated
by the high value of the coefficient of interaction term in the equation for determining Carr's index. Similarly, Figure 3
indicates higher levels of HPMC and silicon dioxide are required for obtaining higher values of CSB; and Figure 4 indicates
that a higher level of silicon dioxide is required to achieve the higher value of CSP.
Figure 4, (All figures are courtesy of the authors.)
For a material to be a good filler–binder, it should be free flowing and at the same time have good compaction properties
(24). The lower values of angle of repose and compressibility index and higher values of crushing strength are indicative
of the same. It was therefore decided that the angle of repose values <25, compressibility index <15, CSB >50 N, and CSP >50
N would be constraints for the selection of the best batch.
Anita Lalwani is an assistant professor in the Department of Pharmaceutics at the K.B. Institute of Pharmaceutical Education and Research, Sector-23, Gh-6 Road, Gandhinagar-382023, Gujarat, India, tel. 91 98983 20018.
Articles by Anita Lalwani
Jolly Parikh is an assistant professor in the Department of Pharmaceutics at A.R. College of Pharmacy and G.H. Patel Institute of Pharmacy, Vallabh Vidyanagar-388 120, Gujarat, India.
Articles by Jolly Parikh
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