Physicochemical Characterization of Grewia ferruginea Hochst. ex A. Rich Mucilage for Potential Use as a Pharmaceutical Excipient

Gum and mucilages from natural sources are in recent times increasingly investigated for pharmaceutical applications. Different studies have shown that the gum and mucilage fraction of various species of the genus Grewia were found to be effective viscosity enhancers, stabilizers, disintegrants, suspending agents, gelling agents, bioadhesives, film coating agents, and binders. However, no study has been conducted on the potential use of Grewia ferruginea mucilage (GFM) as a pharmaceutical excipient. Therefore, this study was aimed at characterizing the Grewia ferruginea bark mucilage for its potential use as a pharmaceutical excipient. The mucilage was extracted from the Grewia ferruginea inner stem bark through aqueous extraction, precipitated with 96% ethanol, dried, and powdered. The powdered mucilage was characterized for different physicochemical properties such as powder property, loss on drying, solubility and swelling index, ash value, pH, viscosity, moisture sorption property, microbial load, and acute oral toxicity. According to the results, the percentage yield of the final dried and powdered GFM was found to be 11.96% (w/w). The density and density-related properties of the mucilage showed good powder flow property. The GFM exhibited pseudoplastic flow behavior. Moisture sorption property of GFM revealed its hygroscopic nature, and its solubility and swelling property was increased with temperature. The pH of GFM was near neutral. Microbial load of the mucilage was within the pharmacopoeial limit, and the oral acute toxicity test revealed that the mucilage is safe up to 2000 mg/kg. From the investigations of this study, it can be concluded that Grewia ferruginea bark mucilage has the potential to be utilized as an excipient in pharmaceutical formulations