Assessment of co-processed composites of Cissus-acacia and Cissus-guar gums as suspending agents in metronidazole benzoate suspension

Abstract

The study evaluated various co-processed hydrophilic polymer composites derived from cissus gum (CG) and acacia gum (CAG), cissus gum and guar gum (CGG) and CG, acacia gum (AG) and guar gum (GG) alone at varying concentrations as suspending agents in the formulation of metronidazole benzoate (MTZB) suspensions. Suspensions containing MTZB, 200 mg/5ml was formulated using 1.5, 2.0 and 3.0 % w/v of either CG, AG, GG, CAG or CCG. The suspensions were evaluated considering sedimentation volume, flow rate, viscosity, pH, freeze-thaw test and redispersibility. The results showed that all the hydrophilic polymers employed yielded enhanced properties of the suspensions following the increase in their respective concentrations leading to enhanced viscosities, reduced flow rates and increased sedimentation volumes with the best outcomes observed as CGG>GG>CG>CAG>AG>Control (p < 0.05) for sedimentation volume; CGG>CG>GG>AG>CAG>Control (p < 0.05) for viscosity and CGG>GG>CG>CAG>AG>Control for flow rate (p < 0.05). Very stable pH was recorded with CG at all the concentrations studied, followed by the CGG, especially at the early days following their preparations. There was no changes in the particle sizes of the MTZB in the products formulated with the CG following the freeze-thaw test (p > 0.05). Other batches exhibiting stable particle sizes after freeze-thaw test were got with 2.0 % w/v of AG, 2.0 % w/v of GG and 2.0 % w/v of CGG (p > 0.05). The batch containing 3.0 % w/v of CGG and the control batch had their p-values = 0.05. These results may be indication that stable suspensions of the MTZB may be obtained with 2.0 % w/v of these hydrophilic polymers. The ease of redispersibility of the MTZB suspensions were in the order GG < CG < CGG < CAG < AG < Control. The best co-processed hydrophilic polymer were those prepared with CG and GG.