[The modern approaches to the determination of the content of elemental impurities in the pharmaceutical substances with the use of inductively-coupled plasma mass-spectrometry].

The elemental impurities contained in the composition of the pharmaceutical dose forms are known to be capable of interacting with their active substances and excipients and of catalyzing their degradation; thereby, they alter stability of the drug products and exert toxic effects on the human tissues. The present publication was designed to report the results of the purity tests for ascorbic acid, valine, and galactose substances by inductively-coupled plasma mass-spectrometry (IBP-MS). This method is recommended for use by the US and EU pharmacopoeias and for the replacement of the traditional test for heavy metals with the use of PbS ethanol suspension.

[The methods for the protection against counterfeit medications. Part 1. The estimation of the quality of metoprolol succinate substance and tablets from different manufacturers in terms of "identity" and "active ingredient content"].

This paper was designed to report the results of analysis of metoprolol succinate substance and tablets obtained from two manufacturers, Akrikhin (Russia) and AstraZeneca (Sweden). The analysis was performed by spectroscopy in the near IR region and followed by the chemometric treatment of the data obtained. The method was used to confirm the "identity" of metoprolol succinate tablets. The approach to distinguishing the differences between pharmaceutical dosage forms produced by different manufacturers is proposed. Also, the method for the qualitative determination of metoprolol succinate in the pharmaceutical formulations has been developed.

[Methods for the protection against counterfeit medications. Part 2. The assessment of interlot dispersion of the metoprolol succinate tablets fabricated by different manufacturers].

This paper reports the results of analysis of the metoprolol succinate tablets fabricated by two different manufacturers, Akrikhin (Russia) and AstraZeneka (Sweden) by near-IR spectroscopy in the combination with the chemometric processing of the data obtained (discriminative analysis). It is concluded that this method is applicable for the assessment of interlot dispersion of the metoprolol succinate tablets.

[Measurement of thallium content in human urine by atomic absorption spectrometry after acute poisoning].

The problem of poisoning with thallium-containing substances continues to be of current concern. According to the Bureau of Forensic Medical Examination, Moscow, specimens of biological materials from more than 20 victims of such poisoning were delivered for analysis in 2006. The total number of thallium poisoning episodes during the period since 1996 exceeded 50. Materials for thallium determination in biological fluids (human blood and urine) using flame atomic absorption spectrometry were prepared by dry mineralization of accurately weighed samples; acidic solutions of the products of mineralization were used for analysis. Due to peculiar kinetic features of thallium ion absorption in the gastro-intestinal tract, blood could not be used as a biological marker of poisoning. The level of thallium in urine samples was found to vary from 1.00 to 4,600 mcg/l (with the estimation of confidence intervals in each case). Results of chemical analysis correlated with pathological symptoms derived from the patients' discharge summaries and literature reports on dose-effect relationships. Based on these findings, practically all the examined cases were characterized as severe acute poisoning.

Kinetic characteristics of biochemical parameters during consupren therapy after allogenic transplantation of the kidney.

Changes in biochemical and common clinical parameters of the blood were detected in patients treated with consupren (cyclosporin) as the main immunosuppressant after allogenic transplantation of the kidney. Kinetic model for evaluation of treatment adequacy was based on therapeutic drug monitoring and monitoring of blood biochemistry in recipients of the primary kidney transplant. The k1, t1/2, C0, clearance (for hemoglobin), conditioned volume of distribution (for cyclosporin) of processes of biochemical parameters (toxicity markers) stabilization within the framework of a single-part kinetic model were determined.

[IR-spectroscopic study of the interaction of chromium salts with native DNA]. / IK-spektroskopicheskoe izuchenie vzaimodeistviia solei khroma s prirodnoi DNK.

Infrared spectra of some unoriented films of DNA contained CrCl3, K2Cr2O7 and Cr2(SO4)3 have been obtained at relative humidities (r.h.) 0 to 93%. Chromium cations were shown to interact with phosphoric groups of DNA molecules. Cr2(SO4)3 or K2Cr2O7 content exceeds 0.1 Cr/P, the sugar-phosphate backbone of the double helix becomes irregular and nucleic bases unstacked, i.e. denaturation of DNA occurs. A very small amount of the salt, less than 0.01 Cr/P contained in DNA films prevents the conformational transition of the double helix from the B to A form induced by r.h. decreasing. The efficiency of the chromium salts in preventing the transition falls in the row: Cr2(SO4)3 > K2Cr2O7-CrCl3.