The effect of formulation additives on the properties of films prepared using Terminalia randii Baker F Gum

Background: Natural polymers are becoming useful excipients in pharmaceutical formulations due to their non-toxic and biodegradable properties. One of their common uses is in the manufacture of polymeric films.Objective: This present work is to evaluate the effect of plasticizer type and polymer type on the properties of Terminalia films.Method: Films were prepared by solvent casting method using Terminalia, xanthan gums and hydroxylpropy lmethylcellulose (HPMC). Terminlia was also combined with xanthan, HPMC at different ratios using propylene glycol and glycerol as plaasticizers. The films were characterized using adherence, folding endurance and mechanical properties were determined using tensile strength and percent elongation. Disintegration was carried out in a disintegration apparatus using distilled water, 0.1M HCl (pH 1.2) and phosphate buffer pH 6.8.Result: Films prepared with Terminalia and those prepared by combining Terminalia and xanthan gums showed adherence. Films plasticized with glycerol had higher folding endurance and tensile strength. When HPMC was combined with Terminalia, the disintegration of the films produced was significantly (p<0.05) reduced at pH 6.8Conclusion: Glycerol plasticizer produced films with optimal properties, while combination of Terminalia gum and HPMC, produced films with optimal properties. Therefore, plasticizer and polymer must be carefully chosen for film formulations

LARVICIDAL POTENTIAL AND MOSQUITO REPELLENT ACTIVITY OF CASSIA MIMOSOIDES EXTRACTS.

This study aims to investigate larvicidal activities of extracts of Cassia mimosoides leaves and pods as a potential agent in vector control of malaria and to evaluate repellent effect against Anopheles gambiae mosquito of the extract formulated in an aqueous cream base. Petroleum spirit, ethanol, water and dichloromethane extracts were tested against third and fourth instar Anopheles gambiae larvae. The petroleum extract was formulated in an aqueous cream base and repellency determined using N-N-diethyl-m-toluamide (DEET) as control. Phytochemical analysis showed the presence of saponins, tannins, anthraquinones, steroids, and flavonoids but absence of cardiac glycosides and alkaloids in powdered C. mimosoides. A dose related response was observed in the mortality rate of the extracts, with 2 mg/ml petroleum ether and dichloromethane extracts achieving 100 % mortality. Larvicidal activity of extracts based on LC50 values was petroleum ether > dichloromethane > ethanol > water. The formulated petroleum ether extract cream had a characteristic odor, hard and smooth texture, skin feeling of smoothness, ease of application by rubbing, easy removal using soap and water, non-irritating effect on skin and an acceptable pH value. The cream containing 2%-6% (w/w) extract and control achieved 100% repellency against mosquitoes after an exposure time of 5 minutes. There was a linear relationship between percent concentration of plant extract in the cream samples and repellent activity. These results suggest that crude extracts of C. mimosoides can be developed as eco-friendly larvicide and mosquito repellent and encourage further effort to investigate the bioactive compounds in the extracts.

Effects of drying methods on the physicochemical and compressional characteristics of Okra powder and the release properties of its metronidazole tablet formulation.

A study has been made of the effects of sun and oven drying methods on the physicochemical characteristics and compressibility of Okra powder and the release properties of its metronidazole tablet formulation. Corn starch was used as the reference standard. The mechanical properties of the tablets were evaluated using crushing strength and friability, while the release properties were determined using the disintegration times and dissolution rates. The results obtained showed that sun-dried Okra powder had smaller particle size, exhibited good flow and possessed higher hydration and swelling capacities compared to the oven dried samples. The compressibility of Okra powders assessed by the indices of plasticity from Heckel (Py) and Kawakita plots (Pk) showed that sun dried Okra powders had higher Py but lower Pk values than the oven-dried Okra powder. Metronidazole tablets formulated with oven dried Okra powder formed stronger tablets than tablets containing sun dried Okra powder. Generally, tablets containing sun dried Okra powders had faster disintegration and dissolution than tablets formulated with oven-dried powder. The results suggest that the choice of drying method during the processing of pharmaceutical raw materials is critical to its physicochemical properties and the release properties of its tablet formulations.