Evaluation of Okra Pectin from Different Genotypes as Effective Suspending Agents in Pharmaceutical Formulations

Abstract

Introduction: Natural suspending agents are increasingly being investigated because of their relative non-toxicity, lesser cost, availability and biocompatibility compared to the currently utilised synthetic and semi-synthetic suspending agents. Pectin, a biopolymer found naturally in plants is gaining increased application in the pharmaceutical and biotechnology industry following its successful functional application as gelling agents, emulsifying agents and fat substitutes in the food industry. This study aimed at evaluating the suspending properties of pectin obtained from five okra (Abelmoschus esculentus L.) genotypes; PL1 (Penkrumah), PL2 (Agbagoma), PL3 (Asha), PL4 (Sengavi) and PL5 (Balabi). Materials and methods: The pectin was extracted using standard protocols and characterised by investigating properties such as degree of esterification. A 5% w/v paracetamol suspension was formulated utilising okra pectin as a suspending agent at concentrations of 0.5%, 1% and 2%w/v and compared to Tragacanth gum suspensions at the same concentrations (0.5%, 1% and 2%w/v). Results: All the extracted pectins had low degrees of esterification (?50 %). The pH, redispersibility, apparent viscosity, sedimentation rate and sedimentation volume of the formulated suspensions were investigated over a 4-week period. The suspensions were stable as evidenced by no significant (p?0.05) fluctuations in pH during the period of study. Compared to when tragacanth was used as a suspending agent, the sedimentation rates, the flow rates of suspensions and redispersibility of the paracetamol suspensions utilising okra pectin were lower while the sedimentation volumes were higher at all the concentrations utilized and met standard requirements. Conclusion: The evidence suggests that all five okra genotypes exhibit better suspending properties when compared to tragacanth gum and thus may be used as an alternative suspending agent.