Nanofabrication of Losartan Potassium Sustained Release Floating Microspheres Using Different Grades of Ethyl Cellulose and Its Insight on Release Profiles.

INTRODUCTION: A sustained release system for losartan potassium designed to delay its residence time in the stomach through the preparation of solvent evaporation technique-based floating microspheres. The influence of the different grades of Ethocel™ such as 4 cps, 10 cps, and 22 cps as well as the drug: polymer ratio on various properties of microspheres were tested. METHODS: Thermal and functional analysis revealed no interaction between the encapsulated drug and polymer. The results indicated that the mean diameter of microspheres increased with a change in grades of ethyl cellulose relating to viscosity. However, the drug incorporation efficiency within ethyl cellulose microspheres decreased with increasing viscosity of ethyl cellulose. RESULTS: The bulk density of the formulations was proportionally dependent on concentration and the viscosity of the polymer, which resulted in a decrease in floating capacity from 90.02% to 73.58%. Moreover, the drug release was indirectly proportional to the viscosity of ethyl cellulose tested. The in vitro release profile exhibited a burst effect with a biphasic release pattern following Fickian diffusion, indicating a diffusioncontrolled release mechanism. CONCLUSION: The results demonstrated that the viscosity of ethyl cellulose significantly affects the floating capacity and drug release pattern from microspheres.

In vivo anti-inflammatory activity of Tabernaemontana divaricata leaf extract on male albino mice.

AIM: To study the in vivo anti-inflammatory activity of Tabernaemontana divaricata leaf extract on male albino mice. METHODS: Aqueous decoction and methanol leaf extracts were tested for their ability to reduce croton oil-induced edema in the mouse ear after topical application. The methanol leaf extract dose-dependently inhibited the croton oil-induced ear edema in mice (ID50 <500 µg·cm(-2)). A bioassay-guided liquid-liquid fractionation of this methanol extract gave four active fractions: water insoluble (F1), hexane (F2), ethyl acetate (F3) and water (F4). RESULTS: The hexane fraction showed a very high activity (42.1% inhibition at 0.7 µg·cm(-2)) as compared to the control. The other fractions were less active (F1: 56.1% at 506.2 µg·cm(-2); F3: 57.3% at 289.3 µg·cm(-2); and F4: 31.9% for 203.8 µg·cm(-2)) while indomethacin gave 48.8% of inhibition at 90 µg·cm(-2). The activity of F1 and F3 may be at least in part explained by the presence of anti-inflammatory flavonoids, while the activity was not correlated to the tannin contents. No compounds were detected in the most active F2 fraction. CONCLUSIONS: The results give a rational support to the traditional use of T. divaricata in tropical India as anti-inflammatory agent.

Antidiarrhoeal activity of leaf extract of celosia argentea in experimentally induced diarrhoea in rats.

In order to scientifically apprise some of the anecdotal, folkloric, ethno medical uses of celosia argentea, the present study was undertaken to examine the antidiarrhoeal properties of alcoholic extract of leaves of Celosia argentea on diarrhoea by using different experimental models. Anti-diarrhoeal effect was evaluated by castor oil induced diarrhoea, charcoal meal test and PGE(2) induced diarrhoea. Loperamide (2 mg/kg) and atropine (0.1mg/kg) were used as standard drugs. Extract was used in 100 and 200 mg/kg dose. It produced dose related anti-diarrhoeal effect. Results suggest that it may act centrally and may inhibit the PGE(2) to give anti-diarrhoeal effects. Result of charcoal meal test also suggests its anti-muscarinic activity.