POTENTIAL OF BRACHYSTEGIA EURYCOMA GUM IN AMELIORATING BRITTLE FRACTURE DURING TABLETING

The aim of the present study is to investigate the potential of Brachystegia eurycoma gum in ameliorating brittle fracture (i.e., lamination and capping) a problem often encountered during tableting. Granules of metronidazole (test drug) were prepared by wet granulation technique using Brachystegia eurycoma or acacia gum at concentrations of 2.5, 5.0, 7.5 or 10%w/w. The resulting granules were evaluated for packing and flow properties. Granules were compressed into tablets with and without a centre hole (as in- built defect) using a compression load of 2.0 arbitrary unit on the load scale. The tablets were evaluated for tensile strength and the data was used to calculate the brittle fracture index (BFI). The compressibility index which is a measure of ease of compaction of the granules upon tapping was < 23.5% while all granules were free flowing with angle of repose <36.90. Increase in binder concentration led to an increase in Pf and T values irrespective of the type of the gum binder used in the formulations. Generally, increasing the binder concentration at a given compression load resulted in a decrease in the brittle fracture tendency of the tablets. For instance, at a binder concentrations of 2.5% w/w the BFI for Brachystegia eurycoma and acacia gum were 0.13 and 0.10 respectively while their corresponding values at binder concentration of 7.5% w/w were 0.06 and 0.08. The study has shown that Brachystegia eurycoma gum is an effective binder that produces harder tablets with low brittle fracture tendency.