Comparative evaluation of the suspending properties of some starches

Abstract

This study investigated the dispersion properties of some locally available starches in comparison with tragacanth in the formulation of suspensions. The starches were extracted from cassava, maize and plantain and the mucilages were employed in the formulation of suspensions at varying concentrations (1-10% w/v). Parameters evaluated were sedimentation rate, flow property, viscosity and redispersibility index. The starches compared favourably with tragacanth in retarding the sedimentation of suspended particles. The sedimented volumes of the suspensions after six weeks storage ranged from 50 ml (cassava), 52 ml (plantain), 55 ml (maize) 60 ml (tragacanth). The starches displayed good flow properties (0.34 – 0.66 ml/s) when compared with tragacanth (0.06ml/s). The redispersibility index of plantain (16) and maize starch (12) suspensions were comparable with that of tragacanth (p< 0.05), while that of cassava (41) was about three times the values of tragacanth or the other starches. This is attributed to the higher viscosity of the cassava starch mucilage. This finding shows that the starches compared favourably with tragacanth used officially in the formulation and stabilization of suspensions and will serve as substitutes to imported minerals and polymeric colloids used in the formulation of suspensions and other extemporaneous preparations.

Keywords: flow properties, starches, sedimentation rate, suspensions

Journal of Pharmaceutical and Allied Sciences Vol. 9 No. 2 (2012)