Comparative Analysis of Two Enoxaparin Sodium Drugs by Heptest.

The optimal conditions for analysis of low-molecular-weight heparin (LMWH) drugs by the Heptest and the metrological characteristics of the Heptest method were determined. The effects of two LMWH preparations of enoxaparin sodium, the domestic drug Enoxaparin sodium (Technologiya Lekarstv, Russia) and the original drug Clexane (Sanofi, France), on the clotting time of human plasma in the Heptest were comparatively analyzed. The mean blood clotting times were calculated for each dilution of each series of Enoxaparin sodium and Clexane based on the results of the Heptest. Graphs of the dependence of the plasma clotting time on the degree of dilution of these drugs were plotted. The shapes of the curves of the dependence of the blood plasma clotting time on the activity of enoxaparin sodium were shown to be similar for both Enoxaparin sodium and Clexane. The Heptest method showed that Enoxaparin sodium (Technologiya Lekarstv, Russia) was comparable to the original drug Clexane (Sanofi, France).

[Clinical implications of physicochemical examination of uroliths and urine].

We have examined composition of uroliths (qualitative and quantitative x-ray tests) and measured 24-h excretion of electrolytes (Cl-, NO2-, NO3-, SO4(2-), PO4(3-), cytrate, isocytrate and uric acid) using ion-exchange chromatography with a conductometric detector. We revealed correlations between ion characteristics, their concentration in the urine before and after treatment and composition of disintegrated uroliths and clinical data. This allowed us to identify some urinary ions which indicate activity of urolithogenesis, predisposition to urolithiasis, production of certain uroliths, reflect some processes running in patients with urolithiasis. We give concentrations of some urinary ions which can be considered normal and deviations which may indicate urolithogenesis.

Chiral high-performance liquid chromatography analysis of alpha-amino acid mixtures using a novel SH reagent--N-R-mandelyl-L-cysteine and traditional enantiomeric thiols for precolumn derivatization.

Several chiral thiols, i.e. traditionally used enantiomerically pure SH reagents and novel N-R-mandelyl-L-cysteine (R-NMC) containing additional chiral center, have been applied as co-reagents in precolumn derivatization with o-phthalaldehyde for enantiomeric HPLC analysis of individual alpha-amino acids and their mixtures. The R-NMC-derived isoindoles as well as adducts with other thiols have a characteristic absorption maximum at 340 nm, and are highly fluorescent allowing detection of 10 microg/l of an amino acid. Investigated 19 amino acids were analyzed separately and in a mixture by a gradient HPLC after precolumn derivatization. The chromatographic behavior of formed isoindoles substantially differs for each of the thiols used for modification. In contrast to traditional enantiomeric thiols application of diastereomeric R-NMC provides higher resolution for alpha-amino acid enantiomers, with L,D-elution order (except for Arg). Combined use of R-NMC and other thiol enlarges the possibilities of this method, allowing accurate chiral analysis of complex amino acid mixtures.