Application of physical-chemical methods in chemical-toxicological analysis of pyroxicam

Abstract

Pyroxicam (4 hydroxy-2 methyl-N-2 pyrydinil-2H-l,2 benzotiazin-3 carboxamide-1,1 dioxide) is used in medicine to treat the rheumatoid polyarthritis, anchylopoetic spondilitis, gout attack, periarthritis, traumatic pains. It concerns to the group of drugs with antiinflamatory features, analgesic. The action mechanism can be explained by the synthesis inhibition of prostaglandines and the inhibition of the synthesis of cyclooxigenase and the migration of leucocytes to the inflammatory focus inhibiting the phagocytosis and releasing of lysosomal hydrolysis. In certain conditions (overdosage, hepatic diseases) pyroxicam possesses toxic features. In this context the study of pyroxicam is a specific interst in biological fluids. As a result we intended to study the factors (the pH values of the medium the extragents polarizing acting during the process of isolation of the compound from the blood serum). Pyroxicam has alkaline properties; it can be extracted from an alkali medium. We used chloroform as an extraagent, which carries a specific character for the compounds in unionized form from biological fluids. The pH value is important, which gives us the opportunity to isolate pyroxicam from biological fluids, its passage from ionized form in a molecular one, which encourages the officiency of extraction with lipophilic solvents. The pyroxicam was isolated from blood serum after acidulation with oxalic acid (pH2.0-2.5) and the proteins sedimentation with threechloracetic acid, then extracted from alkali medium with chloroform. Alkalic extracts underwent spectrophotometric studies at a wave length 247 nm. We applied silicosis plaques on a thin layer within chromatography in the following system of solvents: Chloroform: Acetone (4:1) Rf=0.51; Ethylacetate: Methanol: Ammoniacal solution 25% (85:10:5) Rf=0.17; Ethylacetate Rf=0.38. These methods can be applied in chemical toxicological analysis practice.Acetone (4:1) Rf=0.51; Ethylacetate: Methanol: Ammoniacal solution 25% (85:10:5) Rf=0.17; Ethylacetate Rf=0.38. These methods can be applied in chemical toxicological analysis practice.