Comparison of classic and derivative UV spectrophotometric methods for quantification of meloxicam and mefenamic acid in pharmaceutical preparations.

The methods for quantitative determination of meloxicam and mefenamic acid in pharmaceuticals by classic spectrophotometry - zero order derivative, first and second order derivatives spectrophotometry is described, using "peak - peak" (P-P) and "peak - zero" (P-O) measurements. The calibration curves are linear within the concentration range of 4.0 - 14.

Simultaneous separation of 14 antiarrhythmic drugs and determination of mexiletine and flecainide by capillary zone electrophoresis.

A method using capillary zone electrophoresis was developed for the simultaneous separation of 14 antiarrhythmic drugs belonging to various classes. The drugs are separated on a fused-silica capillary, 90 cm x 75 microm (72 cm effective length), with phosphate and acetate buffers as background electrolytes and UV detection at 217 nm. The effects of buffer pH, temperature, and applied voltage on the migration of the drugs were studied.

Comparative validation of amisulpride determination in pharmaceuticals by several chromatographic, electrophoretic and spectrophotometric methods.

Nine accurate methods for determination of amisulpride in tablets: reversed phase high pressure liquid chromatography (RP-HPLC), aqueous capillary electrophoresis (CE), non-aqueous CE, normal phase (NP) and reversed-phase (RP) high performance thin layer chromatography (HPTLC) with densitometry and videodensitometry, and direct and derivative UV spectrophotometry were developed and validated. The HPLC was carried out using Nova-Pak C8 column and mobile phase consisted of acetonitrile-methanol-phosphate buffer pH 4.50 (15:5:80, v/v/v) with flow rate 1 mL min(-1) and UV detection at 225 nm.

Development and validation of a new high-performance liquid chromatography method for the determination of gliclazide and repaglinide in pharmaceutical formulations.

A new high-performance liquid chromatography method was developed and validated for the quantitation of gliclazide and repaglinide in pharmaceutical formulations. Determination was performed using a LiChroCART RP-18 column, a mobile phase containing acetonitrile-phosphate buffer (pH 2.1; 60 + 40, v/v), and ultraviolet (UV) detection at 225 nm.

Applications of derivative UV spectrophotometry for the determinations of fenbufen and ketoprofen in pharmaceutical preparations.

A methods for the determination of fenbufen and ketoprofen in pharmaceuticals by classical spectrophotometry--zero order derivative, first and second order derivatives spectrophotometry is described. using "peak-peak" (P-P) and, "peak-zero" (P-O) measurements. The calibration curves are linear within the concentration range of 2.

Antioxidative and anti-inflammatory effects of repaglinide in plasma of diabetic animals.

Oxidative stress, defined as an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense, is considered to be an important pathogenic factor in diabetes mellitus and its complications. In diabetic state, ROS might also be implicated in promoting a state of systemic inflammation. Recently, it was demonstrated that antioxidant therapy could be used to stop the initiation and propagation of this inflammatory response.

Comparison of classical and derivative UV-spectrophotometric methods for the quantification of diltiazem and mexiletine.

A first order derivative UV-spectrophotometric method for the determination of diltiazem hydrochloride and mexiletine hydrochloride has been developed and validated. In the assay, the first- and second-order measurements with the use of the "peak-zero" and "peak-peak" techniques were applied. The linear correlation (r < 0.

Application of derivative spectrophotometry for simultaneous determination of quinapril and hydrochlorothiazide in the combination tablets.

A new second-order-derivative spectrophotometric method using zero-crossing technique measures quinapril (QUI) and hydrochlorothiazide (HYD) in 2-component mixtures. The procedure does not require prior separation of components from the sample. QUI was determined at a wavelength of 211.

Polymeric membrane electrodes for selective determination of methiaden.

Polyvinyl chloride matrix membrane ion-selective electrodes for the determination of methiaden hydrochloride based on the ion-pair of methiaden cation with tetraphenylborate anion were prepared using bis(2-ethylhexyl)sebacate, (electrode A), 2-nitrophenyl octyl ether (electrode B). 2-nitrophenyl dodecyl ether (electrode C) and 1-isopropyl-4-nitrobenzene (electrode D) as the membrane solvents. The electrodes exhibit near-Nernstian response in different concentration ranges, depending on the used membrane solvents.

Determination of fleroxacin in pure and tablet forms by liquid chromatography and derivative UV-spectrophotometry.

Derivative UV-spectrophotometric and liquid chromatographic (LC) methods for fleroxacin determination were validated. In the spectrophotometric assay, first-, second-, third-, and fourth-order measurements were applied with the use of peak-zero and peak-peak techniques. The linear correlation between amplitude of the peak and concentration of the examined drug ranged from 2.

Changes in antioxidant status of heart muscle tissue in experimental diabetes in rabbits.

The present study was designed to evaluate the oxidative stress-related parameters in alloxan-induced diabetes in rabbits. After 3, 6, 12 and 24 weeks of hyperglycaemia the enzymatic and non-enzymatic factors were measured in heart tissue of diabetic and control groups. Superoxide dismutase and glutathione peroxidase activities and the contents of total sulfhydryl compounds significantly increased at all time intervals.

Applications of derivative UV spectrophotometry for the determinations of cetirizine dihydrochloride in pharmaceutical preparations.

A method for the determination of cetirizine dihydrochloride in pharmaceuticals by first-, second-, third- and fourth- order derivative spectrophotometry is described, using "peak-peak" (P-P), and "peak-zero" (P-0) measurements. The calibration curves are linear within the concentration range of 7.5-22.

Changes in antioxidant status of lung tissue in experimental diabetes in rabbits.

Objectives: Hyperglycaemia can result in oxidative stress which may affected as cellular tissue damage.

Design And Methods: After 3, 6, 12 and 24 weeks of hyperglycaemia oxidative stress related parameters were measured in lung tissue of diabetic and control rabbits.

Results: Decreased activities of antioxidative compounds and intensification of lipid peroxidation process were found in diabetic lung.