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HPLC of Bioactive Compounds
Lukšanová, Aneta ; Kubíček, Vladimír (advisor) ; Lázníčková, Alice (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Biophysics and Physical Chemistry Consultant: Ing. Vladimír Kubíček, CSc. Student: Aneta Lukšanová Title of thesis: HPLC of bioactive compounds This diploma thesis is focused on finding conditions of HPLC analysis of midazolam and it's two metabolites - 1-hydroxymidazolam and 4-hydroxymidazolam, on method validation and on finding an appropriate internal standard. The analysis was carried out under reversed-phase conditions, the chosen column was POROSHELL 120 EC-C18, 3.0 X 100 NM, 2.7 µm, and a mixture of acetonitrile and ammonium acetate buffer with pH 4.5 in a ratio of 35/65 has been proven to be effective mobile phase. Detection was carried out using the diode array detector with wavelength values 223 nm and 272 nm. The column was thermostated at 25 řC, the analysis time was 10 minutes. Flow rate of mobile phase was 0.700 ml/min. Diazepam was found as a suitable internal standard. The method was validated only for 1-hydroxymidazolam and 4-hydroxymidazolam determination in rat plasma due to a submitter's request. Within the analytic method validation the following parameters were tested: precision, accuracy, lower limit of quantitation, linearity and selectivity.
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HPLC of Bioactive Compounds
Lukšanová, Aneta ; Kubíček, Vladimír (advisor) ; Lázníčková, Alice (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Biophysics and Physical Chemistry Consultant: Ing. Vladimír Kubíček, CSc. Student: Aneta Lukšanová Title of thesis: HPLC of bioactive compounds This diploma thesis is focused on finding conditions of HPLC analysis of midazolam and it's two metabolites - 1-hydroxymidazolam and 4-hydroxymidazolam, on method validation and on finding an appropriate internal standard. The analysis was carried out under reversed-phase conditions, the chosen column was POROSHELL 120 EC-C18, 3.0 X 100 NM, 2.7 µm, and a mixture of acetonitrile and ammonium acetate buffer with pH 4.5 in a ratio of 35/65 has been proven to be effective mobile phase. Detection was carried out using the diode array detector with wavelength values 223 nm and 272 nm. The column was thermostated at 25 řC, the analysis time was 10 minutes. Flow rate of mobile phase was 0.700 ml/min. Diazepam was found as a suitable internal standard. The method was validated only for 1-hydroxymidazolam and 4-hydroxymidazolam determination in rat plasma due to a submitter's request. Within the analytic method validation the following parameters were tested: precision, accuracy, lower limit of quantitation, linearity and selectivity.
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Oxidation of a psychoactive substance fluoromethoxyacetyl fentanyl
Krejčí, Michaela ; Kubíček, Vladimír (advisor) ; Nováková, Veronika (referee)
7 2. ABSTRACT Fluoromethoxyacetyl fentanyl (FMAcF) is a new psychoactive substance that belongs to the group of newly illegally synthesized fentanyl derivatives that have been entering the European drug market since 2009. The aim was to define the electrochemical behavior of FMAcF and to suggest possible oxidation mechanisms. In this research, the electrochemical methods and in situ UV-Vis spectroelectrochemistry were used to study drug oxidation and reduction mechanism. Electrochemical techniques were combined with high performance liquid chromatography with diode array detector. FMAcF in the aqueous medium provided a single oxidation peak whose potential depended on pH. The substance was not reduced under the studied conditions. UV-Vis spectroelectrochemistry showed the formation of a reaction intermediate. The substance was electrolyzed and the UV-Vis absorption spectra of the products were determined. The oxidation mechanism of the substance has been proposed. In future the incubation with liver microsomes will be performed to detect metabolic pathways. Key words: Cyclic voltammetry, Oxidation, Bioactive substance, Fentanyls, Fluoromethoxyacetyl fentanyl
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Influence of Electrolytes on CMC
Šmerdová, Jana ; Kubíček, Vladimír (advisor) ; Lázníčková, Alice (referee)
Souhrn V této diplomové práci bylo použito UV-VIS absorpční spektrofotometrie k měření CMC katonických tenzidů a vlivu elektrolytů na CMC. Dosažené výsledky potvrzují očekávaný trend poklesu hodnot CMC tenzidů se stoupající iontovou silou roztoků. Použitá modifikace metody UV-VIS absorpční spektrofotometrie pro stanovení CMC byla rovněž úspěšná.
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Study of radiolabelling of receptor-specific peptide from the group of gastrin derivatives I
Zeithamová, Jana ; Lázníčková, Alice (advisor) ; Kubíček, Vladimír (referee)
This work studies the radiolabeling of minigastrins using 111 In. For experimental purposes minigastrins 46, 47 and 48 were used with different amino acids sequences. It was made especially for radiochemical purity 111 InCl3 sign, since this parameter is very important for possible future use of these labeled peptides. Another parameter investigated was the monitoring of the stability of radioactively labeled minigastrins. Results were measured using high performance liquid chromatography, the clear evidence of pollution and possible degradation products. The second applied method was performed by instant thin-layer chromatography in several different environments. The objective was to determine the dependence on the purity of the product over time in both short and long time intervals.
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Determination of Lipophilicity of Potential Drugs
Coufalová, Iva ; Kubíček, Vladimír (advisor) ; Nováková, Veronika (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Author: Mgr. Iva Coufalová Consultant: Ing. Vladimír Kubíček, CSc. Thesis Title: Determination of Lipophilicity of Potential Drugs This rigorous thesis deals with the determination of lipophilicity of new synthesized potential drugs based on pyrazine structure by reversed phase high performance liquid chromatography. The theoretical part contains a brief overview of the drugs development and clinical studies, there are also summarized historical and currently common used processes for lipophilicity estimating, including the basic principles of chromatography. Another part of thesis is engaged in to the measurement of specific samples of drugs on a Zorbax ECLIPSE XDB-C8 600 Bar, 50.0x3.0 mm, 1.8 µm column. This column was chosen in order to shorten the retention times of the measured samples compared with C18 column packing. For the lipophilicity values of the examined drugs are considered the logarithm of capacity factor values which were determined by extrapolation to zero concentration of methanol in the mobile phase. In conclusion there was made a comparison of the results with the values previously obtained on a Zorbax ECLIPSE XDB-C18 600Bar, 50.0x4.6 mm, 1.8 μm column and...
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Stability studies of monoclonal antibody nimotuzumab modified with chelator DOTA radiolabelled with lutetium-177 ([177Lu]Lu-hR3(p-SCN-Bn)DOTA)
Petřík, Michal ; Lázníčková, Alice (advisor) ; Kubíček, Vladimír (referee)
The higher expressivity of the gene for the receptor of epidermal growth factor (EGF) and consequently higher number of receptors (EGFR) on the surface of cells is closely linked with the tumour proliferation of these cells and with poor prognosis for patients. For such reason the EGFR became one of the main objectives in the therapy of tumours. Nimotuzumab (also known as h-R3) is humanized monoclonal antibody which blocks receptor for epidermal growth factor. The object of this thesis was to determinate radiochemical purity of this antibody conjugated with bifunctional chelator DOTA and marked by luthecium, possibly purification of this antibody and consequently determination of its stability in different environments. In acetate buffer pH = 7, in an environment of the surplus of competitive ligand EDTA and in plasma of rats. Adequate analytic methods were used for these tasks: high-efficiency liquid chromatography, gel permeation chromatography and chromatography on thin layer. The results of the thesis demonstrated that this way of modification for further radiolabelling is not appropriate for large protein structures such as Nimotuzumab
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Chromatographic Properties of Benzimidazoles
Tyrnová, Lucie ; Kubíček, Vladimír (advisor) ; Jezberová, Michaela (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Lucie Tyrnová Consultant: ing. Vladimír Kubíček, CSc. Title of Thesis: Chromatographic Properties of Benzimidazoles This thesis deals with research considering chromatographic properties of albendazole and its metabolites (albendazole sulfoxide and albendazole sulfone). Measurements were made by Reversed Phase High Performance Liquid Chromatography (RP HPLC). Two columns packed with stationary phases C18 (Zorbax SB and Atlantis T3) were tested during the research. According to a prior calculation there was a chance to expect the columns to show different selectivity during separation albendazole and its metabolites compared to column packed with stationary phase C18 LiChrosper 60 RP-Select B. For the determination of albendazole and its metabolites in biological material by RP HPLC, a part of this thesis was focused on finding a suitable internal standard. Results of the thesis show that the column Zorbax SB is suitable for separation of albendazole and its metabolites, while the column Atlantis T3 gave no satisfactory results. Oxibendazole was successfully tested as the internal standard. Unfortunately the column Zorbax C18 SB does not eliminate important difficulties...
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