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Budapest, Hungary

Gorog S.,Gedeon Richter Plc
Journal of Pharmaceutical and Biomedical Analysis

An overview is presented of the impact of chromatographic method developments on the quality control of pharmaceuticals as of the 1950s up until the present times. This survey is mainly based on the changes in pharmacopeias starting with United States Pharmacopeia (USP) 16, issued in 1960, up to the presently effective USP 34 and European Pharmacopeia 7.2. At the beginning of this period the role of chromatographic methods was negligible and was restricted to classical column chromatography and paper chromatography. However, the invention of high-performance liquid chromatography (HPLC) initiated a rapid paradigm shift in the attitude toward, and the use of, chromatographic methods. As a result, HPLC began a " career" of rapid spreading and development, and by now has undoubtedly become the principal method in pharmaceutical analysis. Likewise, the role of thin-layer chromatography (TLC) and to a lesser extent gas chromatography is also remarkable. The role of these and electrophoretic methods in the identification, assay and purity check of drugs and drug products in the modern pharmacopeias is discussed.As a case study the stability investigation of Depersolone® injection carried out in the 1960s and 35 years later is presented and the information obtainable from the classical and modern approach is compared. © 2012 Elsevier B.V. Source

Gorog S.,Gedeon Richter Plc
Journal of Pharmaceutical and Biomedical Analysis

A critical review of the literature of the analysis of steroid hormone drugs is presented based on 213 publications published between 2004 and 2010. The state of the art of the assay and purity check of bulk drug materials is characterized on the basis of the principal pharmacopoeias supplemented by the literature dealing with their impurity profiling and solid state characterization. The determination of the active ingredients and impurities/degradants in pharmaceutical formulation by HPLC, other chromatographic, electrodriven, spectrophotometric and other methods is also summarized. A short section deals with the application of analytical methods in drug research. The literature of the determination of steroid hormones in environmental samples is summarized in tabulated form. © 2010 Elsevier B.V. Source

Horvath C.,Gedeon Richter Plc
Medical Hypotheses

Migraine is a debilitating disease with a recurring generally unilateral headache and concomitant symptoms of nausea, vomiting and photo- and/or phonophobia that affects some 11-18% of the population. Most of the mechanisms previously put forward to explain the attacks have been questioned or give an explanation only some of the symptoms. Moreover, the best drugs for treatment are still the 20-year-old triptans, which have serious limitations as regards both efficacy and tolerability. As the dura and some cranial vessels are the only intracranial structures capable of pain sensations, a vascular theory of migraine emerged, but has been debated. Recent theories identified the hyperexcitability of structures involved in pain transmission, such as the trigeminal system or the cortex, or an abnormal modulatory function of the brainstem. However, there is ongoing scientific debate concerning these theories, neither of which is fully capable of explaining the occurrence of a migraine attack.The present article puts forward a hypothesis of the possibility of abnormal temperature regulation in certain regions or the overall brain in migraineurs, the attack being a defense mechanism to prevent neuronal damage. Few examinations have been made of temperature regulation in the human brain. It lacks the carotid rete, a vascular heat exchanger that serves in many animals to provide constant brain temperature. The human brain contains a high density of neurons with a considerable energy demand that is converted to heat. The human brain has a higher temperature than other parts of the body and needs continuous cooling. Recent studies revealed unexpectedly great variations in temperature of various structures of the brain and considerable changes in response to functional activation. There is various evidence in support of the hypothesis that accumulated heat in some structure or the overall brain may be behind the symptoms observed, such as a platelet abnormality, a decreased serotonin content, and dural "inflammation" including vasodilation and brainstem activation. The hypothesis postulates that a migraine attack serves to restore the brain temperature. Abnormally low temperatures in the brain can also result in headache. Surprisingly, no systematic examination of brain temperature changes in migraineurs has been published. Certain case reports support the present hypothesis. Various noninvasive technologies (e.g. MR) capable of monitoring brain temperature are available. If a systematic examination of local brain temperature revealed abnormalities in structures presumed to be involved in migraine, that would increase our understanding of the disease and trigger the development of improved treatment. © 2014 Elsevier Ltd. Source

This review reports the most important contributions of the 5th Drug Design & Lead Discovery conference, held in October 2009 in San Diego. The conference was focused on lead-finding strategies and compound optimization. Lectures covered state-of-the-art design strategies, application fragment-based approaches, the impact of ADME properties on lead finding and optimization, and a number of optimization case studies. In addition to the new technologies reported, both fragment-based and optimization case studies provided excellent examples for the lead discovery knowledge space that was discussed in detail during the conference. Copyright © 2010 Prous Science, S.A U or its licensors. All rights reserved. Source

Szakonyi G.,Gedeon Richter Plc | Zelko R.,Semmelweis University
Journal of Pharmaceutical and Biomedical Analysis

Water contents of superdisintegrant pharmaceutical excipients were determined by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy using simple linear regression. Water contents of the investigated three common superdisintegrants (crospovidone, croscarmellose sodium, sodium starch glycolate) varied over a wide range (0-24%, w/w). In the case of crospovidone three different samples from two manufacturers were examined in order to study the effects of different grades on the calibration curves. Water content determinations were based on strong absorption of water between 3700 and 2800cm-1, other spectral changes associated with the different compaction of samples on the ATR crystal using the same pressure were followed by the infrared region between 1510 and 1050cm-1. The calibration curves were constructed using the ratio of absorbance intensities in the two investigated regions. Using appropriate baseline correction the linearity of the calibration curves was maintained over the entire investigated water content regions and the effect of particle size on the calibration was not significant in the case of crospovidones from the same manufacturer. The described method enables the water content determination of powdered hygroscopic materials containing homogeneously distributed water. © 2012 Elsevier B.V.. Source

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