High Performance Liquid Chromatographic Determination ofInactive Carboxylic Acid Metabolite of Clopidogrel in HumanSerum: Application to a Bioequivalence Study

A sensitive and rapid method is described for determination of clopidogrel carboxylic acid (CCA), the inactive metabolite of the antiplatelet agent clopidogrel in human serum. The analytical procedure involves liquid-liquid extraction of the analyte and an internal standard (phenytoin) with ethyl acetate. Amobile phase consisting of 0.05 M phosphate buffer containing triethylamine (0.5 ml/l; pH 5.7)and acetonitrile (56:44; v/v) was used and chromatographic separation was achieved using a C18analytical column at detector wavelength of 220 nm. The calibration curves were linear over a concentration range of 0.05-10 μg/ml of CCAin human serum. The total run time of analysis was 5.5 min. and the lower limits of detection (LOD) and quantification (LOQ) were 0.02 and 0.05 μg/ml, respectively. The method validation was carried out in terms of specificity, sensitivity, linearity,precision, accuracy and stability. The validated method was applied in a randomized cross-over bioequivalence study of two different clopidogrel preparations in 24 healthy volunteers

A Sensitive Liquid Chromatographic Method for the Analysis of Clarithromycin with Pre-Column Derivatization: Application to a Bioequivalence Study

Objective(s)A sensitive liquid chromatographic method for the analysis of clarithromycin- a macrolide antibiotic- in human serum, using pre-column derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) is described. Materials and MethodsThe method involved liquid–liquid extraction of the drug and an internal standard (amantadine) followed by pre-column derivatization of the analytes with FMOC-Cl. A mixture of 0.05 M phosphate buffer containing triethylamine (2 ml/l; pH 3.8) and methanol (17:83, v/v) was used as mobile phase and chromatographic separation was achieved on a Shimpack CLC-ODS column. The eluate was monitored by a fluorescence detector with respective excitation and emission wavelengths of 265 and 315 nm. ResultsThe analytical method was linear over the concentration range of 0.025-10 μg/ml of clarithromycin in human serum with a limit of quantification of 0.025 μg/ml. The assay is sensitive enough to measure drug levels obtained in human single dose studies.ConclusionIn the present method, sensitivity and the running time of analysis have been improved and successfully applied in a bioequivalence study of three different clarithromycin preparations in 12 healthy volunteers

Analgesic and Anti-inflammatory Activity of Teucrium chamaedrys Leaves Aqueous Extract in Male Rats

Objective(s)Current study was undertaken to investigate the analgesic and anti-inflammatory effects of the aqueous extract of Teucrium chamaedrys in mice and rats. Materials and MethodsFor evaluating of analgesic and anti-inflammatory activity, we used the carrageenan- and dextran-induced paw oedema, acetic acid-induced writhing, tail flick and formalin pain tests.ResultsThe extract of T. chamaedrys (50–200 mg/kg) and acetylsalicylic acid (100 mg/kg) produced a significant (P< 0.01) inhibition of the second phase response in the formalin pain model, while only the high dose (200 mg/kg) of the extract showed an analgesic effect in the first phase. The extract also inhibited acetic acid-induced abdominal writhes in a dose-dependent manner. The tail flick latency was dose dependently enhanced by the extract but this was significantly (P< 0.05) lower than that produced by morphine (10 mg/kg). The extract (25–250 mg/kg) administered 1 hr before carrageenan-induced paw swelling produced a dose dependent inhibition of the oedema. No effect was observed with the dextran-induced oedema model. Results of the phytochemical screening show the presence of alkaloids, flavonoids and triterpenoids in the extract.ConclusionThe data obtained also suggest that the anti-inflammatory and analgesic effects of the extract may be mediated via both peripheral and central mechanisms. The role of alkaloids, flavonoids and triterpenoids will evaluate in future studies

Khatabi P, Effects of boswellia papyrifera gum extract on learning and memory in mice and rats

Abstract Objective(s) Learning is defined as the acquisition of information and skills, while subsequent retention of that information is called memory. The objective of the present study was to investigate the effect of aqueous extract of Boswellia papyrifera on learning and memory paradigms in mice and rats. Materials and Methods This study was held at the Department of Pharmacology, Faculty of Pharmacy, Kermanshah University of Medical Science, Kermanshah, Iran from September 2006 to March 2008. Male Wistar rats and male NMRI mice were randomly divided into control, B. papyrifera treated (50, 100, 150 mg/kg, p.o.), and piracetam (150 mg/kg) groups. Radial arm maze (RAM) and Morris water maze (MWM) were the screening tests used to assess the activity of B. papyrifera extract. Results The mice treated with B. papyrifera (50, 100 and 150 mg/kg) or piracetam (150 mg/kg) showed a decrease in number of days required to learned (P&lt; 0.05) and time taken to find food by the learned mice in radial arm maze (P&lt; 0.01). In Morris water maze, rats treated with the above mentioned doses showed dose dependent improvement in spatial learning. Escape latency during swimming in water maze in piracetam and B. papyrifera treated animals was significantly lower (P&lt; 0.01) than control. Swimming distance was also significantly lower (P&lt; 0.05) in the treated groups. Conclusion The results show facilitation of spatial learning and memory processes and thereby validate B. papyrifera traditional use of intelligence improving. The presence of alkaloids, flavonoids and saponins might be responsible for this activity of B. papyrifera

The Effect of Chronic Administration of Aegle Marmelos Seed Extract on Learning and Memory in Diabetic Rats

Objective(s)Diabetes mellitus is associated with disturbances of learning and memory and cognitive functioning. Aegle marmelos Corr. from Rutaceae family is widely used in Iranian folk medicine for the treatment of diabetes mellitus. Considering the beneficial antidiabetic and antioxidant potential of A. marmelos, this study was conducted to evaluate the effect of oral administration of A. marmelos on learning and spatial memory in diabetic rats using Morris water maze test.Materials and MethodsConsidering the beneficial antidiabetic potential of A. marmelos, this study was conducted to evaluate the effect of chronic oral administration of A. marmelos as cognitive enhancer, on learning and spatial memory in diabetic rats using Morris water maze test. Male Wistar rats were randomly divided into normal-control, diabetic-control, and A. marmelos-treated diabetic groups (100, 250 and 500 mg/kg, p.o.). Animals were treated for 4 weeks by A. marmelos or normal saline. Diabetes was induced by a single dose i.p. injection of streptozotocin (45 mg/kg). In each group of animals, spatial learning and memory parameters were analyzed. ResultsClear impairment of spatial learning and memory was observed in diabetic group versus normal-control group. A. marmelos showed dose dependent improvement in spatial learning and memory parameters that swimming time (Escape Latency) in normal-control and A. marmelos-treated diabetic animals rats was significantly (P< 0.01) lower than diabetic-control, while swimming speed was significantly (P< 0.05) higher.ConclusionThe study demonstrated that A. marmelos has significant protective affect against diabetes-induced spatial learning and memory deficits. This effect could be attributed to hypoglycemic, hypolipidemic and antioxidant activity of A. marmelos

Aegle marmelos Extract Can Enhance Memory in Rats: Effect of Aegle marmelos extract on learning and memory

Diabetes mellitus is associated with disturbances of learning and memory and cognitive functioning. Aegle marmelos Corr. from Rutaceae family, is widely used in Iranian folk medicine for the treatment of diabetes mellitus. It decreases blood glucose level by improving glucose tolerance and also has lipid-lowering and antioxidant properties. Considering the beneficial antidiabetic potential of A. marmelos, this study was conducted to evaluate the effect of chronic oral administration of A. marmelos as cognitive enhancer, on learning and spatial memory in diabetic rats using Morris water maze test. Male Wistar rats were randomly divided into normal-control, diabetic-control, and A. marmelos-treated diabetic groups (100, 250 and 500 mg/kg, p.o., 4 weeks). Diabetes was induced by a single dose i.p. injection of streptozotocin (45 mg/kg). In each group of animals, spatial learning and memory parameters were analyzed. A. marmelos showed dose dependent improvement in spatial learning and memory parameters. Swimming time (Escape Latency) in normal-control and A. marmelos-treated diabetic animals rats was significantly lower than diabetic-control, while swimming speed was significantly higher. The study demonstrated that A. marmelos has a significant protective effect against diabetes-induced spatial learning and memory deficits. This effect can be attributed to hypoglycemic, hypolipidemic and antioxidant activity of A. marmelos

High Performance Liquid Chromatography Determination of Sertraline in Human: Quantification of sertraline by HPLC

An accurate and sensitive reversed-phase high-performance liquid chromatograph-ic method for determination of sertraline in human serum is described using 4-chloro-7-nitrobenzofurazan as pre-column derivatization agent. The drug and aninternal standard (azithrimycin) were extracted from serum using a mixture ofdiethyl ether-chloroform and subjected to the pre-column derivatization with thereagent. Analysis of the resulted derivatives was performed on a Lichrosorb CN(250×4.0 mm) column using a mobile phase composed of methanol and sodium phosphate buffer (0.05 M; pH 3.7) containing 2 ml/lit triethylamine (63:37 v/v).Detector response was monitored at excitation and emission wavelengths of 470 and537 nm, respectively. The calibration curve was linear over the concentration range of 2 to 640 ng/ml. The lower limits of detection and quantification were 0.5 and 2ng/ml, respectively. The validation of the analysis was carried out in terms of specificity, sensitivity, linearity, precision, accuracy and stability. The validated method was shown to be accurate, with intra-day and inter-day accuracy from 0.3 to 4.2%and precise, with intra-day and inter-day precision from 2.4 to 15.5%. The drug is detected at concentrations as low as 2 ng/ml in a 0.5 ml serum sample and the described method can be easily applied in human single-dose pharmacokinetic studies of sertraline

3-D Design and Simulation of a Piezoelectric Micropump

The objective of this paper is to carefully study the performances of a new piezoelectric micropump that could be used, e.g., for drug delivery or micro-cooling systems. The proposed micropump is characterized by silicon diaphragms, with a piezoelectric actuation at a 60 V input voltage, and by two passive valves for flow input and output. By means of a 3-D Finite Element (FE) model, the fluid dynamic response during different stages of the working cycle is investigated, together with the fluid&#8211;structure interaction. The maximum predicted outflow is 1.62 &#956;L min &#8722; 1 , obtained at 10 Hz working frequency. The computational model enables the optimization of geometrical features, with the goal to improve the pumping efficiency: The outflow is increased until 2.5 &#956;L min &#8722; 1

A review study on methanol steam reforming catalysts: Evaluation of the catalytic performance, characterizations, and operational parameters

Conventional fossil-based energy sources have numerous environmental demerits; sustainable and renewable sources are attracting the undivided attention of researchers owing to their valuable physical and chemical features. Several industrial-scale technologies are employing hydrogen as a green energy source as the most preferential source. Not only is hydrogen a potent energy carrier but also it is not detrimental to the environment. Among many other hydrogen production processes, steam reforming of methanol (SRM) is deemed a practical method due to its low energy consumption. Cu, Ni, noble metals, etc., are the salient catalysts in SRM. Many researchers have conducted thorough studies incorporating improvement of the catalysts’ activity, mechanism predictions, and the impacts of operational parameters and reformers. This review concentrates on the SRM catalysts, supports, promoters, and the effect of the operational parameters on the process efficiency and H2 production yield. In this regard, the methanol conversion, H2 and CO selectivity, and operating parameters are notably contingent on the surface characterization and chemistry of the catalysts. Herein, Cu-, Ni-, and noble metal-based catalysts on various metal oxide supports, such as Al2O3 and ZnO, are assessed meticulously in the SRM process from the standpoint of mechanism and catalyst characterization. Most of the peer-reviewed studies had encountered agglomeration, metal particle sintering at high temperatures, coke formation, and deactivation of catalysts as the prevalent barriers. Hence, the novel methods of conquering the above-mentioned obstacles are evaluated in this review. Employment of diverse synthetic methods, bimetallic catalysts, distinct catalyst promoters, and unconventional supports, such as metal–organic frameworks, carbon nanotubes, and zeolites, are the salient routes to overcome the metal dispersion and thermal stability issues. In addition, the influence of operational parameters (temperature of the process, steam/carbon ratio, and feed flow rate) has been weighed painstakingly, along with introducing the research gap and future perspectives in the territory of SRM catalysts