Utilization of Bombax Ceiba Mucilage as an Emulsifying Agent in Castor Oil Emulsion Formulation

This study evaluated the potential of mucilage extracted from Bombax ceiba as a natural emulsifying and stabilizing agent in oil-in-water emulsions, compared to commercial acacia gum. Emulsions prepared with varying concentrations of Bombax ceiba mucilage exhibited concentration-dependent improvements in stability, with creaming index decreasing from 35% at 0.6% (w/v) to 17% at 1.2% (w/v), approaching the performance of acacia gum (15% at 1.0% w/v). Organoleptic properties revealed a characteristic brown color and mucilaginous taste for Bombax ceiba emulsions, consistent with unrefined tree gums and attributed to natural pigments, in contrast to the off-white, neutral-tasting refined acacia gum. Rheologically, Bombax ceiba mucilage emulsions displayed significantly higher viscosity and pronounced shear-thinning (pseudoplastic) behavior, compared to the low-viscosity, near-Newtonian profile of acacia gum (typically 500–874 cP). This enhanced viscosity provides superior anti-creaming effects via reduced droplet mobility per Stokes’ law, offering advantages in applications requiring prolonged stability or contact time. Despite minor organoleptic drawbacks common to many unrefined plant mucilages, Bombax ceiba mucilage demonstrates comparable physical stability to acacia gum at slightly higher concentrations and confers desirable rheological benefits as both emulsifier and thickener. As a locally abundant resource in tropical regions including Africa and Asia, it represents a promising, sustainable alternative to imported acacia gum for pharmaceutical emulsions, such as oral suspensions, topical creams, and mucoadhesive formulations.