Protective effect of 313-hydioxy-2,3-dihydrowithanolide F against CCI4-induced hepatotoxicity has been assessed and the compound was found to possess marked protective effect. A comparison of the protective properties showed that it is more active than hydrocortisone on a weight basis.

Pharmacological investigations with alcoholic extract, total alkaloids and aqueous extract of the fruits of W i t hania c o a g u l a n s showed the presence of central nervous system depressant effect characterised by decreased spontaneous activity and potentiation of pentobarbitone hypnosis. However, the extracts showed no analgesic and anticonvulsant activity. In addition, alcoholic extract and total alkaloids showed a significant antiinflammatory effect in acute inflammation induced with egg albumin, subacute inflammation induced with formalin and granulation tissue formation by cotton pellet method.

H elicobacter pylori (H. pylori), the major culprit for peptic ulcer, has a unique way of survival in harsh acidic environment of the stomach by colonizing deep in the gastric mucosal layer. Failure of conventional therapies against H. pylori for complete eradication has major limitations like low residence time of delivery system in stomach, poor penetration of drug in gastric mucosa, acidic degradation of antibiotics, and development of antibiotics resistance. The poor penetration of antibiotics through thick viscoelastic mucosal gel results in incomplete eradication of H. pylori. Various investigators have formulated novel gastro-retentive drug delivery systems such as floating systems, mucoadhesive systems, pH-sensitive gel systems, and muco-penetrating delivery systems for increasing the concentration of antibiotic in close proximity to the site of H. pylori infection. This review summarizes the novel drug delivery approaches investigated during the last few years and suggests that a high eradication rate can be achieved by therapy comprising of muco-penetrating delivery systems of antibiotics against H. pylori.

S tomach-specific floating tablet of metronidazole based on the buoyancy and bioadhesion concept was prepared with a purpose to retain the drug in stomach for longer duration and helps in releasing the drug in the antrum region of gastric mucosa, a safe heaven for Helicobacter pylori. This research work systematically studied the effects of various polymeric blends of bioadhesive polymers namely chitosan and carbopol 971P with low density polymer-methocel K100LV on the desired in vitro drug release profile in the stomach, buoyancy, swelling index, and mucoadhesion of tablet formulation. Chitosan and carbopol 971P concentration significantly influence the in vitro drug release and bioadhesion strength. An increase in buoyancy was observed with increase in Methocel K100LV concentration in the polymeric blend. The increase in buoyancy and drug release was obtained in the presence of microcrystalline cellulose, sodium bicarbonate, and sodium citrate. The optimum formulation provides desired high drug concentration (~35%) during 1 hour and sustained release up to 12 hours, following the Higuchi model. The mechanism of release of metronidazole from the floating bioadhesive tablets was anomalous diffusion transport. The studies indicated successful formulation of gastroretentive compressed tablet with excellent controlled release, mucoadhesion, and hydrodynamic balance.