DARU, Journal of Pharmaceutical Sciences
Volume:10 Issue: 4, Winter 2002

Abstract: The high mortality rate associated with significant bleeding from stress ulceration has promoted efforts to prevent this complication in critically ill patients. Gastric pH is a key factor in the pathogenesis of stress ulceration and maintaining a pH of 4 or greater reduces the risk for development of the gastric ulceration. Our aim was to compare effects of intravenous bolus administration and continuous intravenous infusion of ranitidine on gastric pH in critically ill patients at the intensive care unit (ICU). Twenty patients who met the inclusion criteria were entered this prospective, randomized, cross over study. A total of 1500 gastric pH measurement was obtained for each phase of the study. Continuous infusion of ranitidine maintained a gastric pH greater than 4 over a longer period than that of bolus administration (22.1 hrs vs. 14.2 hrs, respectively; P<0.001). The pH-monitoring device which was made locally, was comparable to a standard international device. This study showed that continuous infusion of ranitidine was more effective than administration of an equivalent dose of the drug by bolus in maintaining the appropriate gastric pH required for the prevention of stress ulceration.

Abstract: The effect of propranolol and isoproterenol on the hydrolysis of 4- nitrophenylbutyrate (PNPB) by the purified human plasma cholinesterase was studied. During the hydrolysis of PNPB, enzyme obeyed to Michaelis-Menten model. Propranolol was found to be a competitive inhibitor, and isoproterenol yielded a complex inhibition pattern. It could be explained that the inhibitory effect of propranolol shows noncooperativity between subunits of human plasma cholinesterase upon binding of PNPB. In contrast, isoproternol inhibitory effects indicate more than one type of binding sites on this enzyme.

Abstract: Water-distilled essential oil from aerial parts of Ferula ovina (Boiss.) Boiss. growing wild at the vegetative stage in Isfahan province Iran was analyzed by GC/MS. Forty-three compounds consisting 86.7% of the total components were identified in the oil which was obtained in 1.0% (v/w) yield. Among them, carvacrol (9.0%), alpha-pinene (8.2%), geranyl isovalerate (7.2%) and geranyl propionate (7.0%) were the major components.

Abstract: Ginkgo biloba (GB) preparations are now among the leading herbal medicines that exert a broad spectrum of possible clinical applications. Several methods have been reported for quantification of ginkgolides of GB and its pharmaceutical preparations and the HPLC techniques are now considered to be the method of choice. However, most reported HPLC methods are not simple and their work-up procedure are inadequate. The present paper describes a simple and non-expensive method for extraction and determination of ginkgolides A and B in GB leaves and their phytopharmaceuticals. The method is based upon extraction of ginkgolides from aqueous solution by activated charcoal, followed by extraction with Methanol and injection of the Methanolic solution into chromatographic system. Ginkgolides were separated on an ODS column with a mobile phase of water-methanol (67:33 v/v) at a flow rate of 1.0 ml/min and were detected at 220 nm. The mean recoveries of ginkgolide A and B were 97 and 98.4%, respectively. This method is simple and can be used for routine analysis of GB extracts and phytopharmaceuticals preparations.

Abstract: Ginkgo biloba (GB) preparations are now among the leading herbal medicines that exert a broad spectrum of possible clinical applications. Several methods have been reported for quantification of ginkgolides of GB and its pharmaceutical preparations and the HPLC techniques are now considered to be the method of choice. However, most reported HPLC methods are not simple and their work-up procedure are inadequate. The present paper describes a simple and non-expensive method for extraction and determination of ginkgolides A and B in GB leaves and their phytopharmaceuticals. The method is based upon extraction of ginkgolides from aqueous solution by activated charcoal, followed by extraction with Methanol and injection of the Methanolic solution into chromatographic system. Ginkgolides were separated on an ODS column with a mobile phase of water-methanol (67:33 v/v) at a flow rate of 1.0 ml/min and were detected at 220 nm. The mean recoveries of ginkgolide A and B were 97 and 98.4%, respectively. This method is simple and can be used for routine analysis of GB extracts and phytopharmaceuticals preparations.