National Repository of Grey Literature 129 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Nanofiltration
Hudečková, Hana ; Kučera, Radim (advisor) ; Holas, Ondřej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Nanofiltration Diploma thesis Candidate: Hana Heidrová Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: PharmDr. Tomáš Holas, Ph.D. Nanofiltration is a pressure-driven membrane process which is characterized by using semipermeable membranes with approximately 1 nm pores. This method is used abundantly for the separation of substances with low molecular weight. It is used for example in the process of product isolation in pharmaceutical industry. This diploma thesis is focused on the description of the behaviour of three commercially produced nanofiltration membranes and also on testing of their potential use in the production of ergot alkaloids. The theoretical part is focused especially on the description of pressure-driven membrane processes, the use of nanofiltration in various areas and also on current and historical use of ergot alkaloids in therapy and on the description of their properties. The practical part is oriented particularly on examination of effect of various experimental parameters on the retention of selected ergot alkaloids (primarily of lysergic and isolysergic acid). The results are compared and critically analysed. Keywords: pressure-driven...
Usage of HPLC and UHPLC-MS/MS techniques for clinical research
Matoušová, Kateřina ; Matysová, Ludmila (advisor) ; Doležal, Rafael (referee) ; Kučera, Radim (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Mgr. Kateřina Kučerová Supervisor: assoc. prof. PharmDr. Ludmila Matysová, Ph.D. Consultant: assoc. prof. RNDr. Lenka Kujovská Krčmová, Ph.D. Title of Dissertation Thesis: Usage of HPLC and UHPLC - MS/MS techniques for clinical research The dissertation thesis is dealing with the extraction techniques and with development, optimization and validation of chromatographic methods for the determination of omeprazol which is drug from the group of proton pump inhibitors, and retinol as a new potential biomarker of kidney damage. The theoretical part of the thesis is focused on detailed description of the individual analytes, their clinical significance, options of determination and the matrix in which the target analytes were determined. Furthermore, the preparation of the sample before the analysis is discussed and validation recommendations related to chromatographic methods used in both pharmaceutical analysis and bioanalysis are also mentioned. In the experimental part the development, optimization and validation of UHPLC methods and their subsequent use are described in detail. The pharmaceutical-analytical part of the work describes the determination of omeprazole in new suspension preparations,...
The use of HPLC in the field of chiral separations V.
Burda, Jakub ; Kučera, Radim (advisor) ; Kastner, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Jakub Burda Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Title of Thesis: The employment of HPLC in the field of chiral separations V. Continuously growing requirements of regulatory authorities for the quality and safety of medicines put a high pressure on manufacturers. Last decades are marked by optically pure drugs, whose developement goes hand in hand with developement of chiral syntheses and separations. The most used method in the field of separations are direct separations using chiral stationary phases. The most often used carrier for these stationary phases is silica, which may contain metal impurities on its surface, negatively impacting separation process. The focus of this thesis was testing of influuence of chromatographic conditions on chiral and achiral interactions of seven selected analytes with stationary phase. Column with native β-cyclodextrin as chiral selector was used for the testing. 1
Stationary phase based on ionic liquids for separation of ibuprofen impurities
Komůrková, Lenka ; Kučera, Radim (advisor) ; Kastner, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Mgr. Lenka Komůrková Supervisor: Doc. PharmDr. Radim Kučera, Ph.D. Title of diploma thesis: Stationary phase based on ionic liquids for separation of ibuprofen impurities. Rigorous thesis was focused on the determination of ibuprofen and its pharmacopoeial impurities B, E, F and J using gas chromatography coupled with mass spektrometry. The analysis was performer on a SLB-IL 100 capillary column with a stationary phase based on ionic liquid - 1,9-di(3-vinylimidazolium)nonane bis(trifluoromethy) sulfonyl imide. Ibuprofen was derivatized with alkyl chloroformate (isobutyl chloroformate, ethyl chloroformate, heptafluorochloroformate) in the presence of the appropriate alcohol (isobutanol, ethanol, heptafluorobutan-1-ol). The derivatization reaction was successful for all derivatizing agents used. However, the use of ethyl chloroformate appeared to be the best due to the negligible amount of non-derivatized ibuprofen residue. Subsequently, the amount of added alcohol, the derivatization of ibuprofen depending on the retention of the sample in the ultrasonic bath and the influence of the ibuprofen solution on the derivatization and subsequent analysis were investigated....
Development of HPLC method for evaluation of tryptophan metabolites
Pšenčíková, Barbora ; Kastner, Petr (advisor) ; Kučera, Radim (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Barbora Pšenčíková Supervisor: PharmDr. Petr Kastner, Ph.D. Title of thesis: Development of HPLC method for evaluation of tryptophan metabolites The essential amino acid tryptophan is a precursor of several important bioactive compounds. In recent years it was found out that tryptophan metabolites are involved in the pathogenesis of many diseases, including neurodegenerative and psychiatric disorders, autoimmune diseases, or cancer. Therefore, the analytical methods for simultaneous determination of tryptophan and its metabolites are highly required. The purpose of this diploma thesis was to develop an optimal HPLC method for determination of tryptophan and its metabolites (kynurenine, kynurenic acid, serotonin and 5-hydroxyindole-3-acetic acid) and to consider all the possible options of determination of quinolinic acid and melatonin. The chromatographic separation was carried out by Supelco Ascentis Express F5 column, 2.7 μm particle size, 15 cm × 3 mm, using spectrophotometric and fluorescence detection. Parameters of detection were for kynurenine UV detection 369 nm, 254 nm, fluorescence detection Ex/Em: 369/475; for kynurenic acid UV detection 244 nm; for...
LC-HRMS analysis of selected drugs in biological material II.
Švarcová, Kristýna ; Kučera, Radim (advisor) ; Bavlovič Piskáčková, Hana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Kristýna Švarcová Consultant: RNDr. Martin Mžik, Ph.D. Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Title: LC-HRMS analysis of selected drugs in biological material II. Anxiety disorders affect up to 25 % of the population in their life, the lifetime prevalence is 13,6 %. Insomnia affect at least one third of the population in their life, the prevalence is 15-40 %. Drugs used to treat anxiety and insomnia easily cross the blood-brain barrier and affect the CNS. It is therefore necessary to determine the correct dosing schedule and monitor treatment. The result is optimization of treatment, reduction of side effects and increased patient adherence to treatment. The rapid qualitative and quantitative analysis for urgent cases of intoxication is also needed. This diploma thesis deals with development and optimization of an extraction method for selected benzodiazepines (alprazolam, bromazepam, diazepam, chlordiazepoxide, clonazepam, midazolam, oxazepam) and zolpidem in human serum. Subsequently, the whole analytical method was validated for use in clinical practice using the UHPLC-HRMS. Protein precipitation with acetonitrile was the most suitable sample preparation...
The influence of solubility and adsorption on plastic materials on transport experiments
Šilhanová, Marie ; Kučera, Radim (advisor) ; Váňová, Nela (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Student: Marie Šilhanová Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Title of diploma thesis: The influence of solubility and adsorption on plastic materials on transport experiments From transport experiments on cell culture models we get valuable information about transport mechanism of drugs in organism. In vitro experiments are conducted for example on Transwell type inserts. During the experiment it was discovered that the results are not homogeneous, and the quantity of a substance in the solution decreases apparently, the reason behind this is inadequate solubility of lipophilic substances or their adsorption on the surface of plastic materials used in the experiment. Due to these problems we experience significant bias. This thesis is focused on antivirotics that did not perform well during transport experiments. First, HPLC/MS methods were developed, and they were used for concentration measurement of samples containing individual antivirotics. The drugs were tested under wide range of conditions so possible changes in effects of adsorption on plastic surfaces and solubility of drugs could be observed. The substances were divided into groups based on...
The electrochemical reduction of the nitro group in a flow reactor
Jankových, Miroslav ; Kučera, Radim (advisor) ; Zimčík, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical chemistry and Pharmaceutical analysis Student: Miroslav Jankových Supervisor: doc. PharmDr. Radim Kučera, PhD. Consultant: PharmDr. Tomáš Holas, PhD. Title of diploma thesis: The electrochemical reduction of the nitro group in a flow reactor The aim of this diploma thesis is to study the electrochemical reduction within the flow reactor. The combination of these two methods provides enviromentaly-friendly and interesting method for the manufacturing of active pharmaceutical ingredients. Our object was to find out if the reaction really goes on. After that our goals were to optimize the reaction parameters. We executed some of the experiments to understand the parameters such as: flow rate, voltage, electric current, electrolyte. These parameters we combined to see their effect on the reaction results. The outcome of the thesis is mainly basic information about impact of parameters mentioned above. From the series of experiments the best parameters are flow rate 0,1 ml.min- 1 , voltage 0,8 - 2,0 V, electric current 100 - 150 mA, electrolyte NH4Cl, reaching conversion up to 96%.
The employment of HPLC for separation of bioconjugates of azaphthalocyanines II.
Sčensná, Anna ; Kučera, Radim (advisor) ; Lochman, Lukáš (referee)
7 ABSTRACT Charles University, Faculty of Pharmacy in Hradec Králové Department Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate Anna Sčensná Supervisor doc. PharmDr. Radim Kučera, Ph.D. Title of Thesis The employment of HPLC for separation of bioconjugates of azaphthalocyanines II. Bioconjugates of azaphthalocyanines are studied as dark quenchers in molecular probes to monitor real-time PCR. The detection is based on energy transfer between a fluorophore and a quencher, both labelled to the oligonucleotide chain. The fluorophore emits a radiation and the dark quencher switches it off. The efficiency of fluorescence quenching depends on the distance between fluorophore and quencher. Probes can be mono-labelled, in which two oligonucleotides are used, one attached to a fluorophore and the other one to a quencher. The second type is called double-labelled probes, which contain both (fluorophore and quencher) on the same oligonucleotide chain. An unbound probe is randomly coiled, thus fluorophore and quencher approach each other. The fluorescence is not emitted. After hybridisation with a complementary chain, the quencher and fluorophore move away from each other. The terminal nukleosid at 5'end of Taq-man probe is cleaved after hybridisation, where the fluorophore is bonded. After...
Usage of HPLC and UHPLC-MS/MS techniques for clinical research
Kučerová, Kateřina ; Matysová, Ludmila (advisor) ; Doležal, Rafael (referee) ; Kučera, Radim (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Mgr. Kateřina Kučerová Supervisor: assoc. prof. PharmDr. Ludmila Matysová, Ph.D. Consultant: assoc. prof. RNDr. Lenka Kujovská Krčmová, Ph.D. Title of Dissertation Thesis: Usage of HPLC and UHPLC - MS/MS techniques for clinical research The dissertation thesis is dealing with the extraction techniques and with development, optimization and validation of chromatographic methods for the determination of omeprazol which is drug from the group of proton pump inhibitors, and retinol as a new potential biomarker of kidney damage. The theoretical part of the thesis is focused on detailed description of the individual analytes, their clinical significance, options of determination and the matrix in which the target analytes were determined. Furthermore, the preparation of the sample before the analysis is discussed and validation recommendations related to chromatographic methods used in both pharmaceutical analysis and bioanalysis are also mentioned. In the experimental part the development, optimization and validation of UHPLC methods and their subsequent use are described in detail. The pharmaceutical-analytical part of the work describes the determination of omeprazole in new suspension preparations,...

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See also: similar author names
1 KUČERA, Richard
5 Kučera, Radek
3 Kučera, Roman
2 Kučera, Rudolf
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