[Development and validation of methodology of quantitative determination of sibutramine in dietary supplements by high performance liquid chromatography].

Sibutramine is a highly effective drug for the treatment of obesity. In this regard, unscrupulous manufacturers can add sibutramine as a biologically active synthetic substance prohibited for use in the composition of dietary supplements. Thus, the problem associated with the illegal circulation of such dietary supplements is especially actual, given the scale of the sale of these products. The development and validation of methods for the determination of sibutramine in dietary supplements for slimming (anorexigenic action) for the purpose of quality control in order to ensure the quality of dietary supplements when introduced into civil circulation at customs and on the market. The aim of the study - to develop a method for the quantitative determination of sibutramin in dietary supplements for weight loss by high performance liquid chromatography (HPLC) and to validate it. Material and methods. For the quantitative determination of sibutramine in dietary supplements, we used an Agilent 1100 high performance liquid chromatograph with a UV-detector. The stationary phase was a chromatographic column C18 NUCLEOSIL 4.6×150 mm, particle size 5 µm. The mobile phase contained 0.05 M formate buffer pH 4.0 and acetonitrile in a ratio of 40:60 (by volume). Results and discussion. A methodology has been developed for the determination of sibutramine in dietary supplements for weight loss, which makes it possible to control the quality of dietary supplements. Based on the obtained chromatograms, the specificity was determined; the plant components did not influence the determination of sibutramine in model mixtures. The suitability of the chromatographic system was determined: the retention factor of the compound - 2.222 (more than 2.0), N - 5776 theoretical plates (more than 5000), T peak of sibutramine - 0.939 (not more than 1.5). Within the analytical area of the linearity method: R2=0.9993 (over 0.9950). ε=0.46% (does not exceed 1.5%), the confidence interval includes the value of 100%, the calculated value of the Student's criterion tcalc (2.47) was less than the tabular ttable (2.80), which proved the correctness of the methodology. The precision of the results was determined by the obtained RSD value, which was 0.91% (less than 1%). Limit of detection (LOD) and limit of quantification (LOQ) took values of 0.1 and 1.0%, respectively. The range of measured concentrations was 0.01-20.0 mg/g. Conclusion. As a result of the studies, the method for sibutramine determination in dietary supplements with anorexigenic action was tested and can be used in quality control of dietary supplements.

[On the issue of the detection of pregabalin and lorazepam in the cases of their joint presence for the purpose of chemical toxicological studies]. / Izuchenie pregabalina i lorazepama pri sovmestnom prisutstvii dlia tselei khimiko-toksikologicheskogo issledovaniia.

Data on the detection of joint presence of pregabalin and lorazepam in the biological objects and material evidence. Aim of this study is to develop a method of the detection of pregabalin and lorazepam in urine. The proposed approach to sample preparation of a biological object and the detection of lorazepam and pregabalin allows the detection of toxicants in cases of their joint presence. It can be used in the analysis of urine in cases of acute poisoning for detoxification therapy or chemical toxicological analysis as a preliminary and confirmatory study for the presence of abuse of these drugs.

[The application of the screening techniques for the purpose of chemical toxicological and forensic chemical analysis]. / Skriningovye metody v khimiko-toksikologicheskom i sudebno-khimicheskom analize.

The application of the screening techniques for the purpose of chemical toxicological and forensic chemical analysis has the objective to detect and identify the life-threatening substances within the shortest possible time period for distinguishing them from a large number of other chemical compounds amenable to the toxicological evaluation. Such methods acquire special importance for forensic chemical expertise in the cases of a negative result of the primary examination. The present article provides information about the history of development of the screening techniques.