sUMMARY
Its developed the optimal chromatographic conditions bisoprolol in general and specific solvent systems for further screening . Bisoprolol has optimal value within 0.5 Rf in experimentally chosen mobile phase consisting of chloroform - isopropyl alcohol - ethyl acetate - ammonium hydroxide solution of conc.( 40: 9.5: 0.5 by volume).
Key words: thinlayerchromatography, bisaprolol, identification, mobilephase, systemofsolvents
Introduction
Bisoprolol refers to a drug that is widely used in cardiology practice, from the group of в-blockers, belongs to —List of essential medicines of WHO”. The main indications for application are hypertension, coronary heart disease, heart failure, heart rhythm disorders, etc.
In therapeutic doses it has no internal sympathomimetic activity, 80-90% of the administered dose absorbs in the gastrointestinal tract and high concentration achieves 2-4 hours after admission, biotransformation in the liver, the half-life is 9-12 hours. In acute poisoning typically nausea, vomiting, diarrhea, bradycardia, blood pressure falls, the central nervous system depression occur.Analysis of published data shows the growing trend of acute poisoning by bisaprololTherefore, for the rapid diagnosis of laboratory of bisaprolol we need highly sensitive and selective methods that meet the modern requirements of chemical and toxicological analysis. These methods include thin-layer chromatography (Lagutkina T.P. et al., 2011; Kokorina N.O., 2013). Different causes of poisoning: suicidal, criminogenic, iatrogenic, etc. The purpose of this study is to develop and improve techniques for the detection of bisoprolol by TLC.
Materials and methods
Drug substance used in this work is bisaprolol (British Pharmacopoeia, 2009.-V.I & II); solvents and reagents are of the category —reagent grade” and —analytical grade”. Thin-layer chromatography was used to remove impurities: chromatographic chamber size 235h170h120, chromatographic plate —Sorbfil PTLC-UV” (—Sorbfil”, Russia); UV chromatoscope, microcapillaries of 2 ul (Russia). Quantitative determination was performed on an SF-2000 (OKB, Russia), in cells with a layer thickness of 10 mm.
Results and Discussion
Bisoprolol was isolated by liquid-liquid extraction in advance from the urine by chloroformisopropyl alcohol at a ratio of 8:2 with pH 10-11. In order to select the chromatographic conditions, allowing achieving selective separation of bisoprolol, its chromatographic behavior was studied in different solvent systems.
The mobile phase which was used for the TLC screening of bisoprolol was selected by a number of eluotropic range of Stahl and on the recommendation of the International Association of Toxicologists for substances exhibiting basic properties, among frequently used solvents such as toluene, acetone, methyl alcohol, ethyl, isopropyl, dioxane and chloroform.Bisoprolol, which has in its structure a tertiary nitrogen atom, gives good detection with Dragendorff reagent, which corresponds to international recommendations of TIAFT, FDA and the Center for Forensic Medicine of the Republic of Kazakhstan.
In order to select the optimal mobile phase with a total chromatographic system, following solventswere selected: chloroform-ethanol (40:10), chloroform-n-butanol-ammonium hydroxide solution conc. (35: 14.5: 0.5), chloroform-isopropyl alcohol-ethyl acetate-ammonium hydroxide solution conc. (40: 9.5: 0.5), toluene, acetone, alcohol, ammonium hydroxide solution conc. (45: 45: 3: 2).Mobility of bisoprolol in common solvent systems were evaluated based on Rf, which are within 0.2-0.8, indicating the effectiveness of these solvent systems.
Bisoprolol has optimal value within 0.5 Rf in experimentally chosen mobile phase consisting of chloroform-isopropyl alcohol-ethyl acetate-ammonium hydroxide solution conc. (40: 9.5: 0.5). Spot at this phase are separated selectively and compactly, without any —tails”.
Further investigation in particular solvent systems, stains of bisoprolol on chromatography system was eluted in ethyl alcohol.In systems recommended for confirmatory analysis with TLC screening of bisoprolol spots have spots in compact systems-toluene-isopropyl alcohol solution conc ammonium hydroxide (30: 14.5: 0.5).
Detectors used are: UV light, iodine vapor, Dragendorff reagent modified by Mounier.
Conclusions
Optimum chromatographic conditionswere designed for bisoprolol in general and specific solvent systemsfor further screening tests.
REFERENCES
1. Кокорина, Н. О. Определение лекарственных препаратов в биожидкостях методом высокоэффективной жидкостной хроматографии / Н. О. Кокорина, В. П. Новоселов, М. А. Ханина // Сибирский медицинский журнал - 2008. - Т. 23. -№4.-С.51 -53.