Розробка та валідація ВЕРХ-методики кількісного визначення ізосорбіду динітрату в матричних гранулах

Isosorbide dinitrate is a universally recognized drug for the relief of angina attacks. Today, prolonged forms of isosorbide dinitrate are of great interest due to their high antianginal efficacy and lower frequency of side effects that are characteristic for drugs with immediate release.Aim. To develop the procedure for the quantitative determination of isosorbide dinitrate in matrix granules using high performance liquid chromatography and validate it.Results. To determine isosorbide dinitrate by the method of high performance liquid chromatography with UV-detection the optimal chromatographic conditions were selected taking into account the effect of excipients in the composition of the medicine. To prove the possibility of applying the procedure proposed in the further analysis of matrix granules of isosorbide dinitrate its validation was carried out. Such validation parameters as specificity, linearity, repeatability, accuracy, intermediate precision, limit of detection and limit of quantification, robustness were assessed using model solutions.Experimental part. The chromatographic researches were performed using liquid chromatograph Shimadzu LC-20AD XR with diode-array detector under the following conditions: chromatographic column – Supelco Discovery C18 (150 × 4.6 мм, 5 мкм); mobile phase – water R – buffer solution with (pH 4.7) – methanol R2 (35:10:55); elution mode – isocratic; flow rate of the mobile phase – 1.0 mL/min.; detection wavelength –220 nm; software – LCsolution, 1.24.SP.1 version.Conclusions. A new procedure for the quantitative determination of isosorbide dinitrate in matrix granules has been developed using high performance liquid chromatography. Its validation has been carried out, and its acceptability has been proven.Изосорбида динитрат – общепризнанное средство для купирования приступов стенокардии. Сегодня большой интерес представляют пролонгированные формы изосорбида динитрата ввиду их высокой антиангинальной эффективности и меньшей частоты побочных эффектов, характерных для препаратов с немедленным высвобождением.Цель. Разработать методику количественного определения изосорбида динитрата в матричных гранулах с использованием высокоэффективной жидкостной хроматографии и провести ее валидацию.Результаты. Для определения изосорбида динитрата методом высокоэффективной жидкостной хроматографии с УФ-детектированием были подобраны оптимальные хроматографические условия, учитывающие влияние вспомогательных веществ в составе лекарственного средства. Для доказательства возможности применения предложенной методики в дальнейшем анализе матричных гранул изосорбида динитрата была проведена ее валидация. Такие валидационные параметры, как специфичность, линейность, сходимость, правильность, внутрилабораторная точность, предел обнаружения и предел количественного определения, робастность были оценены с помощью модельных растворов.Экспериментальная часть. Хроматографические исследования проводили на жидкостном хроматографе Shimadzu LC-20AD XR с диодно-матричным детектором в следующих условиях: хроматографическая колонка Supelco Discovery C18 (150 × 4,6 мм, 5 мкм) подвижная фаза – вода Р – буферный раствор (рН 4,7) – метанол Р2 (35:10:55); режим элюирования – изократический; скорость подвижной фазы – 1,0 мл/мин; длина волны детектирования – 220 нм; программное обеспечение – LCsolution, версия 1.24.SP.1.Выводы. Разработана новая методика количественного определения изосорбида динитрата в матричных гранулах с использованием высокоэффективной жидкостной хроматографии. Проведена ее валидация и доказана приемлемость ее применения.Ізосорбіду динітрат – загальновизнаний засіб для купірування нападів стенокардії. На теперішній час великий інтерес представляють пролонговані форми ізосорбіду динітрату, зважаючи на їх високу антиангінальну ефективність та меншу частоту побічних ефектів, характерних для препаратів з негайним вивільненням.Мета. Розробити методику кількісного визначення ізосорбіду динітрату в матричних гранулах з використанням високоефективної рідинної хроматографії та провести її валідацію.Результати. Для визначення ізосорбіду динітрату методом високоефективної рідинної хроматографії з УФ-детектуванням були підібрані оптимальні хроматографічні умови з врахуванням впливу допоміжних речовин у складі лікарського засобу. Для доведення можливості застосування запропонованої методики у подальшому аналізі матричних гранул ізосорбіду динітрату було проведено її валідацію. Такі валідаційні параметри, як специфічність, лінійність, збіжність, правильність, внутрішньолабораторна точність, межа виявлення та межа кількісного визначення, робастність були оцінені за допомогою модельних розчинів.Експериментальна частина. Хроматографічні дослідження проводили на рідинному хроматографі Shimadzu LC-20AD XR з діодно-матричним детектором за таких умов: хроматографічна колонка Supelco Discovery C18 (150 × 4,6 мм, 5 мкм); рухома фаза – вода Р – буферний розчин (рН 4,7) – метанол Р2 (35:10:55); режим елюювання – ізократичний; швидкість рухомої фази – 1,0 мл/хв; довжина хвилі детектування – 220 нм; програмне забезпечення – LCsolution, версія 1.24.SP.1.Висновки. Розроблено нову методику кількісного визначення ізосорбіду динітрату в матричних гранулах з використанням високоефективної рідинної хроматографії. Проведено її валідацію і показано прийнятність для застосування

FEATURES OF OPERATION OF A SUBSYSTEM OF TECHNOLOGICAL PROTECTION BOOSTER COMPRESSOR UNITS OF THE UNIVERSITY. WAY OF MODERNIZATION

The paper discusses options for upgrading the system of technological protection (TP) of the compressor and assesses the feasibility of these measures.В работе рассматриваются варианты модернизации системы технологических защит (ТЗ) компрессора и оценивается целесообразность применения данных мер

O1 Serogroup Cholera Vibrios Isolated from the Rostov-on-Don Water Bodies in the Course of Surveillance in 2008–2012

Identified are the peculiarities of biological properties and origin of cholera vibrio O1 serogroup strains isolated from the Rostov-on-Don water bodies in the course of surveillance in 2008–2012. 41 atoxigenic V. cholerae O1 strains have been isolated from 767 water samples and investigated. Stable tendency of isolation of increased numbers of atoxigenic V. cholerae O1 strains over time has been demonstrated. In addition, in the strains under study detected have been the genes of additional pathogenicity factors, by PCR genotyping using specific primers for 45 nucleotide sequences associated with V. cholerae pathogenicity. The strains have also been classified according to 19 VNTR-genotypes grouped into 6 clusters based on VNTR-typing using exclusive copyright locus-specific primers. Discovered have been the strains with similar genotypes though isolated at different points both throughout the year and over the period of several years. These ones have probably been imported. They are characterized by a capacity to persist in ambient water bodies for a certain period of time

Cholera Forecast for the Year 2019 Based on Assessment of Epidemiological Situation Around the World, Across CIS and Russia in 2009–2018

Analysis of cholera incidence for the period of 2009–2018 was performed. The upward tendency in the morbidity rate dynamics around the world (compared to 2009) with an average annual growth rate of 5,352 % was revealed. For the first time during the 7th pandemic caused by V. cholerae O1 El Tor, WHO reported 1227391 cases of cholera world-wide in 2017, out of which 1032481 (84.1%) were registered in Yemen, where the war continues and one of the largest epidemics in the world. There have been cross-border epidemiological complications in several African countries. Endemic foci continue to exist and spread in Asia, Africa and the Caribbean. Under the epidemiological surveillance in Russia, 744 strains of V. cholerae El Tor – ctxA– tcpA–, ctxA– tcpA+ and V. cholerae О139 ctxA– and tcpA– were isolated from the surface water bodies, as well as single strains of El Tor ctxA+ tcpA+. As a result of INDEL- and  PCR-genotyping, the isolation of strains with identical genotypes and new ones was established. To make the prognosis for 2019, the risk of activation (continuation) of the cholera epidemic process in the world was assessed, taking into account emergencies of different origin and risk factors. The cholera forecast at the global level and in  Russia for 2019 is unfavorable

SAGES consensus recommendations on an annotation framework for surgical video

Background: The growing interest in analysis of surgical video through machine learning has led to increased research efforts; however, common methods of annotating video data are lacking. There is a need to establish recommendations on the annotation of surgical video data to enable assessment of algorithms and multi-institutional collaboration. Methods: Four working groups were formed from a pool of participants that included clinicians, engineers, and data scientists. The working groups were focused on four themes: (1) temporal models, (2) actions and tasks, (3) tissue characteristics and general anatomy, and (4) software and data structure. A modified Delphi process was utilized to create a consensus survey based on suggested recommendations from each of the working groups. Results: After three Delphi rounds, consensus was reached on recommendations for annotation within each of these domains. A hierarchy for annotation of temporal events in surgery was established. Conclusions: While additional work remains to achieve accepted standards for video annotation in surgery, the consensus recommendations on a general framework for annotation presented here lay the foundation for standardization. This type of framework is critical to enabling diverse datasets, performance benchmarks, and collaboration

Variability of the quasi-2-day wave observed in the MLT region during the PSMOS campaign of June-August 1999

A network of 15 northern hemisphere radars has been used to measure horizontal winds in the mesosphere and lower thermosphere during the PSMOS campaign of Summer 1999. The radars are sited at latitudes ranging from 21°N to 75°N and longitudes from 142°E to 157°W. The data were examined to investigate the Northern Hemisphere structure of the quasi-2-day planetary wave during the interval June-August. The amplitude of the 2-day wave was found to exhibit great day-to-day variability. In particular, significant periodic fluctuations in amplitude occurred with periods of 8-10 and 14-17 days. These modulations were strongest in July and largely absent in June and August. In July, the wave activity can be resolved into three westward-propagating waves with zonal wave numbers of 2, 3 and 4. The periods associated with these wave numbers were 53-56, 48-50 and 42-43 h, respectively. The simultaneous presence of at least two spectral components with periods close to each other may serve to explain the observed amplitude modulations as a result of a beating between different spectral components. An earlier analysis of the planetary-wave field during this interval has revealed a westward propagating ∼16-day wave with zonal wave number 1 (Journal of Atmospheric and Solar-Terrestrial Physics 64 (2002b) 1865-1896). A non-linear interaction between this ∼16-day planetary wave and the (3,0) Rossby-gravity mode (the 2-day-wave) provides a possible mechanism to generate the above ∼42 h/wavenumber 4 wave and the ∼55 h/wavenumber 2 waves as sum and difference secondary waves. A bispectral analysis was used to further investigate non-linear interactions between members of the planetary-wave field and suggested a number of interactions occur within the planetary-wave field, but that some of the interactions also involve the non-migrating diurnal tide with zonal wavenumber 6. © 2004 Elsevier Ltd. All rights reserved

New Approaches to the Modeling of Dissolution of Medicinal Drugs and their Exemption from Tablets

Розроблено модель з використанням бутстреп-методу для оцінки функції розподілу вивільнення лікарського препарату в людському організмі. Розглянуто застосування методу для препарату Трізіпін-Лонг. Для описання розчинності силденафіла цитрату у системі пропіленгліколь–ПЕГ-400 запропоновано модифіковане рівняння Жуйбана-Акрі. З використанням моделі підібрані умови достатнього розчинення препарату.A model is developed using the bootstrap method to evaluate the distribution function of the drug release into the human body. The application of the method for Trizipine-Long is considered. To describe the solubility of sildenafil citrate in the propylene glycol–PEG-400 system, a modified Jouban-Akree equation is proposed. Using the model, the conditions for sufficient dissolution of the preparation are chosen.Разработана модель с использованием бутстреп-метода для оценки функции распределения высвобождения лекарственного препарата в человеческом организме. Рассмотрено применение метода для препарата Тризипин-Лонг. Для описания растворимости силденафила цитрата в системе пропиленгликоль–ПЭГ-400 предложено модифицированное уравнение Жуйбана-Акри. С использованием модели подобраны условия достаточного растворения препарата

Recent advances on thermoelectric materials

By converting waste heat into electricity through the thermoelectric power of solids without producing greenhouse gas emissions, thermoelectric generators could be an important part of the solution to today's energy challenge. There has been a resurgence in the search for new materials for advanced thermoelectric energy conversion applications. In this paper, we will review recent efforts on improving thermoelectric efficiency. Particularly, several novel proof-of-principle approaches such as phonon disorder in phonon-glasselectron crystals, low dimensionality in nanostructured materials and charge-spin-orbital degeneracy in strongly correlated systems on thermoelectric performance will be discussed.Comment: 12 pages, 12 figure

Global-scale tidal variability during the PSMOS campaign of June-August 1999: Interaction with planetary waves

During the PSMOS Global-scale tidal variability experiment campaign of June 1-August 31, 1999, a network of radars made measurements of winds, waves and tides in the mesosphere/lower-thermosphere region over a wide range of latitudes. Clear evidence was found that fluctuations in tidal amplitudes occur on a global scale in both hemispheres, and that at least some of these fluctuations are periodic in nature. Modulation of the amplitude of the 12 h tide was particularly evident at periods of 10 and 16 days, suggesting a non-linear interaction with planetary waves of those periods to be responsible. In selected cases, the secondary waves predicted from non-linear theory could be identified and their zonal wave numbers determined. In some, but not all, cases the longitudinal structure of the secondary waves supports the theory of planetary-wave/tidal interaction being responsible for the observed tidal modulation. It was noted also that beating between a 12.4-lunar and the solar tide could produce a near 16-day modulation of the 12 h tide amplitude that is frequently observed in late summer. © 2002 Elsevier Science Ltd. All rights reserved