Montelukast inhibits caspase-3 activity and ameliorates oxidative damage in the spinal cord and urinary bladder of rats with spinal cord injury.

Spinal cord injury (SCI) leads to an inflammatory response that generates substantial secondary damage within the tissue besides the primary damage. Leukotrienes are biologically active 5-lipoxygenase products of arachidonic acid metabolism that are involved in the mediation of various inflammatory disorders including SCI. In this study, we investigated the possible protective effects of montelukast, a leukotriene receptor blocker, on SCI-induced oxidative damage. Wistar albino rats (n=24) were divided randomly as control, vehicle- or montelukast (10mg/kg, ip)-treated SCI groups. To induce SCI, a standard weight-drop method that induced a moderately severe injury at T10 was used. Vehicle or montelukast were administered to the injured animals 15 min after injury. At seven days post-injury, neurological examination was performed and rats were decapitated. Blood samples were taken to evaluate leukotriene B4 levels, and pro-inflmamatory cytokines (TNF-α, IL-1ß) while in spinal cord and urinary bladder samples malondialdehyde (MDA), glutathione (GSH), luminol chemiluminescence (CL) levels and myeloperoxidase (MPO) and caspase-3 activities were determined. Tissues were also evaluated histologically. SCI caused significant decreases in tissue GSH, which were accompanied with significant increases in luminol CL and MDA levels and MPO and caspase-3 activities, while pro-inflammatory cytokines in the plasma were elevated. On the other hand, montelukast treatment reversed these parameters and improved histological findings. In conclusion, SCI caused oxidative tissue injury through the activation of pro-inflammatory mediators and by neutrophil infiltration into tissues, and the neuroprotective and antiapoptotic effects of montelukast are mediated by the inhibition of lipid peroxidation, neutrophil accumulation and pro-inflammatory cytokine release. Moreover, montelukast does not only exert antioxidant and antiapoptotic effects on the spinal cord, but it has a significant impact on the bladder tissue damage secondary to SCI.

Food effect on bioavailability of modified-release trimetazidine tablets.

This study aimed to investigate a food effect on the bio-availability of modified-release (MR) trimetazidine tablets in 36 healthy volunteers. Trimetazidine, an anti-ischemic drug, protects the myocardial cell from the harmful effects of ischemia. The authors investigated the effect of being under a fasting or fed state at the time of drug intake on the bioavailability of trimetazidine 35-mg MR tablets in a randomized, open-label, crossover, 2-arm, 4-period, 2-sequence bioequivalence study design with a 14-day washout period. Plasma concentration of trimetazidine was assayed in timed samples with a validated high- performance liquid chromatography/mass selective detector that had a lower limit of quantification of 2.5 ng/mL. Test and reference formulations gave a mean trimetazidine C(max) of 63.26 ng/mL and 69.18 ng/mL for the fasting state and 64.19 ng/mL and 63.11 ng/mL for the fed state, respectively. The AUC(0-tlast) mean of trimetazidine was 726.31 ng·h/mL and 733.01 ng·h/mL for the fasting state and 706.40 ng·h/mL and 691.40 ng·h/mL for the fed state for test/reference formulations. There were no significant differences in pharmacokinetic parameters between the 2 formulations and the fasting/fed states. The authors showed that there is no food effect and no need for a 4-period study to evaluate the bioequivalence of trimetazidine MR tablets.

Clinical study on the bioequivalence of two tablet formulations of flurbiprofen.

Flurbiprofen (CAS 5104-49-4) is a member of phenylalkanoic acid derivative group of nonsteroid anti-inflammatory drugs. It exhibits anti-inflammatory, analgesic and antipyretic activities. Two different tablets containing flurbiprofen (FLU) were investigated in 24 healthy volunteers to prove the bioequivalence between both treatments after single oral dose administrations. Fluroben 100 mg tablet and 100 mg tablet of the originator product were used as test and reference preparation respectively. The study was performed open label, randomized, two period cross-over design with 15 days wash out period. Blood samples were taken up to 24 hours for pharmacokinetic profiling. The plasma concentrations of flurbiprofen were determined with validated HPLC-UV method. Maximum plasma concentration (Cmax) of FLU 19,143.65 ng/ml and 19,164.22 ng/ml were found for test and reference formulation respectively. Areas under the plasma concentration time curve AUC(0-infinity), of 118 501.4 ng.h/ml and 111,339.8 ng.h/ml were calculated test and reference formulation respectively. Primary target parameters AUC (0-infinity) and Cmax, both of them were tested parametrically by analysis of variance (ANOVA); 90% confidence intervals were between 100.5%-111.18% for AUC(0-infinity), and 87.6%-115.0% for Cmax. All these values were within the acceptance range (80%-125%) for bioequivalence studies.

The effect of hydroxy metabolites of clarithromycin to the pharmacokinetic parameters, and determination of hydroxy metabolites ratio of clarithromycin.

Clarithromycin is a broad-spectrum macrolide antibacterial agent which is effective both in vitro and in vivo against the major pathogens responsible for respiratory tract infections. Clarithromycin's principal metabolite is 14-(R) hydroxyclarithromycin (14-OH-clarithromycin). The other metabolite, namely 14-(S) hydroxyclarithromycin is inactive. The purpose of this study was to show the hydroxylation of CLA at the 14 position to form the R and S epimers and to determine the metabolic ratio of 14ROHCLA/CLA and 14SOHCLA/CLA for understanding the metabolization. This study suggest that in healthy adults, the individual variations in therapeutic responses to clarithromycin can be assumed by taking the drug and its metabolites ratios. Clarithromycin and metabolites ratios increase during metabolization.

The effect of hydroxy metabolites of clarithromycin to the pharmacokinetic parameters, and determination of hydroxy metabolites ratio of clarithromycin.

Clarithromycin is a broad-spectrum macrolide antibacterial agent which is effective both in vitro and in vivo against the major pathogens responsible for respiratory tract infections. Clarithromycin's principal metabolite is 14-(R) hydroxyclarithromycin (14-OH-clarithromycin). The other metabolite, namely 14-(S) hydroxyclarithromycin is inactive. The purpose of this study was to show the hydroxylation of CLA at the 14 position to form the R and S epimers and to determine the metabolic ratio of 14ROHCLA/CLA and 14SOHCLA/CLA for understanding the metabolization. This study suggest that in healthy adults, the individual variations in therapeutic responses to clarithromycin can be assumed by taking the drug and its metabolites ratios. Clarithromycin and metabolites ratios increase during metabolization.