Studies of human and veterinary drugs' fate in environmental solid samples--analytical problems

The improvement of medical care worldwide is one of the reasons for the increasing production of pharmaceutical products. Human medicines are affordable to a greater proportion of the world's population. But a significant amount of used pharmaceuticals can create problems--accessibility to high volume production pharmaceuticals contributes to an increased contamination in the environment and the possibility of adverse effects on humans and animals. Many of these substances and their metabolites end up in the soil, sediments, and sludge. Knowledge regarding the environmental occurrence of pharmaceutical products is increasing, but information in the peer-reviewed literature regarding the fate and effects of most pharmaceuticals is limited. One of the reasons for this lack of data is that, until now, there have been few analytical methods capable of detecting these compounds at the low levels, which might be expected in the environment. This review article covers recent developments in the analysis of pharmaceuticals in environmental solid matrices (including soil, sediments, and sludge). We will report applications of different solid sample extraction methods, and current advances in liquid chromatography coupled with mass spectrometry for detection and identification of selected drugs in sludge, soils, manure, and sediments.     

Determination of pipecuronium bromide and its impurities in pharmaceutical preparation by high-performance liquid chromatography with coulometric electrode array detection

A sensitive and selective HPLC method with coulometric electrode array detection for the determination of pipecuronium bromide and its four impurities has been developed. The coulometric electrode array detection at increasing potentials from +300 to +900mV of the porous graphite electrode versus the palladium reference electrode was used. The limit of detection and quantitation for pipecuronium bromide was 8 and 25ngml(-1), respectively. This elaborate method for the simultaneous analysis of pipecuronium bromide and its impurities proved to be fast, precise, accurate, sensitive, and could be applied to analysis in substances and in pharmaceutical preparations.     

HCl/DMF for enhanced chemoselectivity in catalytic hydrogenolysis reactions

An improved, chemoselective hydrogenolysis method has been developed. By employing a solvent-acid combination (i.e., DMF-aq HCl) we were able to favor debenzylation rather than aromatic hydrogenation and acid-mediated bond cleavage which are the two main drawbacks of these reactions. The generality of the method, which was primarily developed as a solution to a carbohydrate problem, is shown by the successful hydrogenolysis of 1,8-naphthalide, a previously unsolved problem.     

The zwitterion of <Emphasis Type="Italic">N</Emphasis>-(2-carboxyphenyl)-4-dimethylaminebenzylideneimine

The crystal and molecular structures of N-(2-carboxyphenyl)-4-dimethylaminebenzylideneimine and its protonated form have been determined. The Schiff base exists as the zwitterion, which is stabilized by the intramolecular ionic hydrogen bond. According to quantum-mechanical calculation results this tautomeric form is energetically unfavorable but in the solid and liquid state the intermolecular interactions support zwitterionic form.     

Thermovision diagnostics in chosen spine diseases treated by whole body cryotherapy

The non-invasive infrared technique was used in case of the thermal imaging of patients suffering from spine diseases. Measurements were performed for the group of 50 patients during whole body cryotherapy at the second, fifth and tenth day of the rehabilitation cycle. An enhancement of the profile of skin temperature due to body cooling caused an increase in the diagnostic sensitivity of thermovision. The temperature parameters such as temperature contrast (ΔT = T _max ? T _min) and relative change of contrast ratio defined as (ΔT)/(T _mean) in the region of interest (ROI’s) were used to point out differences between the healthy patients and patients suffering from ankylosing spondylitis, sciatica and spondyloarthrosis. The value of the thermovision diagnostic in the case of spine diseases was confirmed by statistical analysis.     

An Improved Synthesis of Oxazinones Using Molecular Sieves

Abstract: Oxazinones are important chiral reagents in the synthesis of both proteinogenic and nonproteinogenic amino acids. Large scale synthesis of oxazinones has been a problem. The use of molecular sieves in the final step to remove ethanol has helped to obtain the cyclized product in three hours.