Evaluation of Grewia ferruginea Hochst ex A. Rich Mucilage as Suspending Agent in Metronidazole Benzoate Suspension.

Various species of the genus Grewia have been investigated for different pharmaceutical applications as excipients, yet a study on the potential use of Grewia ferruginea mucilage (GFM) as a suspending agent is lacking. Thus, this study is aimed at evaluating the efficacy of Grewia ferruginea mucilage (GFM) as a suspending agent in metronidazole benzoate suspension. The suspensions were prepared using 0.5%, 1%, 1.5%, and 2% w/v of GFM and compared with suspensions prepared from xanthan gum (XGM) and sodium carboxyl methyl cellulose (SCMC) in similar concentrations. The prepared suspensions were evaluated for visual appearance, pH, rheology, sedimentation volume, redispersibility, degree of flocculation, and in vitro drug release profile. Stability study was done at different storage conditions for three months. The results indicated that all the prepared suspension formulations exhibited pseudoplastic flow characteristics with viscosity imparting ability of the suspending agents in the order of XGM > GFM > SCMC (p < 0.05). The flow rate and redispersibility of the formulations prepared with GFM were significantly lower than those with SCMC and higher than those prepared with XGM. At 0.5% w/v suspending agent concentrations, the sedimentation volume of the formulations was in the order of XGM > GFM > SCMC (p < 0.05). However, at all other concentrations, the sedimentation volume of the formulations prepared with GFM had similar results with XGM but exhibited significantly higher sedimentation volume than SCMC. The formulations with GFM showed a higher degree of flocculation at 0.5% w/v concentration but were comparable at 1.5% w/v with XGM containing formulations. The pH, assay, and in vitro release profile of all assessed formulations were within the pharmacopial limit. Thus, based on the finding of this study, it can be concluded that Grewia ferruginea bark mucilage has the potential to be utilized as a suspending agent in suspension formulations.

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.

Evaluation of Acid-Modified Ethiopian Potato (Plectranthus edulis) Starch as Directly Compressible Tablet Excipient.

Ethiopian potato is one of the tuber-bearing members of the family Lamiaceae. It is an indigenous crop in Ethiopia and important source of starch. Unprocessed native starches are structurally weak and functionally restricted for application in pharmaceutical technologies. Consequently, starch is usually modified either chemically or physically to make it convenient for industrial use. The aim of the study was to prepare and characterize acid-modified Ethiopian potato starch (AMEPS) and evaluate its functionality as a direct compressible excipient in tablet formulations. The extracted starch from Ethiopian potato tuber was modified using 6% HCl concentration for 8 days, then dried using oven and spray drying techniques, and subsequently evaluated and compared with the native Ethiopian potato starch (NEPS) and S1500® as a direct compressible excipient. Acid modification of the NEPS decreased the moisture content and swelling power while increased the percent solubility. The X-ray diffraction revealed that both the NEPS and AMEPS have B-type crystal patterns. The AMEPS showed improved flowability compared to the NEPS. This improvement was further enhanced by the spray drying process. The compactability study revealed that the tensile strength of spray-dried AMEPS (16.76 kg/cm2) was significantly higher than that of the spray-dried NEPS (7.07 kg/cm2) and S1500® (11.66 kg/cm2). The AMEPS was less sensitive to lubricants compared to the NEPS and Starch 1500®. Similarly, the dilution potential of the AMEPS was superior to the NEPS and S1500®. The AMEPS accommodated up to 50% of paracetamol while the NEPS and S1500® were able to hold only up to 30%. Pharmacopoeial specifications for disintegration and dissolution were met by the paracetamol tablets prepared by AMEPS. Thus, considering all the results obtained, spray-dried AMEPS could be a potential alternative directly compressible tablet excipient.