Evaluation of Local Gum of Acacia polyacantha as a Suspending Agent in Metronidazole Benzoate Suspension Formulations

Abstract

The local gum of Acacia polyacantha was evaluated as a suspending agent in metronidazole benzoate suspensions in comparison with Acacia senegal and NaCMC at concentration range of 1-4% (w/v). The resulting  suspensions were evaluated for their sedimentation volume (%), degree of flocculation, rheology, redispersibility, and dissolution rate. Stability studies were performed for 3 months. The apparent viscosities were in the order of NaCMC>A. polyacantha>A. senegal. The redispersibilities of A. polyacantha
and A. senegal were comparable but better than those of NaCMC. The sedimentation volumes (%) of the suspensions were higher for NaCMC followed by A. polyacantha and then A. senegal. KH2PO4 employed as a flocculating agent increased the sedimentation volume of the suspensions prepared with A. polyacantha whereas formulations with A. senegal and NaCMC were unaffected. All suspensions showed a release of greater than 85% of drug within 1 h. The results of stability studies showed that all suspension formulations were stable. From the foregoing, it can be concluded that A. polyacantha could be used as an alternative suspending agent.

Keywords: Acacia polyacantha, Acacia senegal, suspending agent, rheology, metronidazole benzoate