National Repository of Grey Literature 36 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Enantiomeric separation of drugs and their metabolites II
Verešpejová, Natália ; Nobilis, Milan (advisor) ; Mokrý, Milan (referee)
Tramadol is centrally acting opioid analgesic drug. It is converted in liver by the enzyme CYP2D6 into active substance O-desmethyltramadol, responsible for analgesia. In clinical practise it is used as racemate. Each enantiomer displays different properties: (-)-tramadol inhibits noradrenaline reuptake and (+)-tramadol, which is therapeutically more effective, inhibits serotonin reuptake. It is indicated for the treatment of mild to moderate pain. This Bachelor's thesis deals with possibilities of determination of drug tramadol and its main metabolite in plasma by chromatographic separation methods, which are currently modern and progressive. Using chiral HPLC analysis with different types of detection, the drug was determined with high sensitivity and selectivity. Individual publications provide pharmacokinetic data of tramadol and its metabolite after oral administration of a single dose of drug to healthy volunteers. The determinations differ by chromatographic conditions, sample preparation, chemicals used and mainly total time of analysis. The results are stated and compared in the summary table.
Analytical evaluation of drugs using HPLC IV.
Mojšová, Kristína ; Mokrý, Milan (advisor) ; Nobilis, Milan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Analysis Candidate: Kristína Mojšová Supervisor: RNDr. Milan Mokrý, CSc. Title of master's thesis: Analytical evaluation of drugs using HPLC IV. This thesis describes development of the suitable method for ketoprofen analysis by high performance liquid chromatography. For this aim a LiChro CART® 125-4 Lichrospher® 100 RP-18 (5 μm) column was used as a stationary phase and mobile phase contained mixture of methanol and aqueous KH2PO4 buffer (pH 3,4) in a ratio of 60:40 (v/v). The flow rate was set to 1 ml/min, temperature on the column was 25 řC and substances were detected at a wave length of 254 nm. Under these conditions final retention time of ketoprofen was 7,9 minutes. Benetazon was chosen as an appropriate internal standard for the quantitative evaluation. In the next part we were looking for suitable conditions for the chiral separation of the analyzed drug by using normal and reverse mode. Separation of ketoprofen's enantiomers was carried out on a Chiralcel OD-R, 250 x 4,6 mm, from Daicel Chemical Industries using a mobile phase of heptane and 2-propanol in a ratio of 97:3, with the addition of 0,6 ml formic acid. At a flow rate of 0,7 ml/min, retention times took about 20 minutes....
Optimization of chromatographic parameters for chiral separation of biologically active compounds
Novák, Martin ; Kučera, Radim (advisor) ; Nobilis, Milan (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Chemistry and Pharmaceutical Analysis Student: Bc. Martin Novák Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: Mgr. et Mgr. Rafael Doležal, Ph.D. Title of diploma thesis: Optimization of chromatographic parameters for chiral separation of biologically active compounds. The diploma thesis was focused on the development of a HPLC-UV method for the determination of K 1277 enantiomers of systematic name N-(2-((6-chloro-1,2,3,4-tetra- hydroacridin-9-yl)amino)hexyl-2-amino-3-(1H-indole-3-yl) propylamide dihydrochloride, which is one of the compounds from the tacrine-tryptophan hybrids group. These tacrine-tryptophan hybrids could be considered as promising candidates of potential drugs against Alzheimer's disease. The thesis brings an explanation of basic characteristic of chiral molecules, principles of chiral separation, pathophysiology, clinical manifestation and treatment of Alzheimer's disease and short characteristic of tacrine-tryptophan hybrids in the theoretical section. The aim of my diploma thesis was to find the optimal chromatographic conditions for separation of K 1277 enantiomers synthesized from tacrine and tryptophan fragments. The experimental part deals with the development of the chiral...
Modern separation techniques for the analysis of biological material in clinical research
Kasalová, Eva ; Solich, Petr (advisor) ; Nobilis, Milan (referee) ; Friedecký, David (referee)
Charles University, Faculty of Pharmacy in Hradec Kralove Department of Analytical Chemistry Candidate: Mgr. Eva Kasalová Supervisor: Prof. RNDr. Petr Solich, CSc. Supervisor specialist: Assoc. Prof. RNDr. Dagmar Solichová, Ph.D. Title of Doctoral Thesis: Modern separation techniques for the analysis of biological material in clinical research This doctoral thesis deals with development and validation of a chromatographic determination of liposoluble vitamins and with optimization of biological materials preparation. Clinical monitoring of these vitamins, especially vitamin D in different biological materials is one of the most discuss theme in the last decade. In the theoretical part of this dissertation the target analytes - vitamins A, E and D with their biological activity are characterized - as well as the biological material used in the Research Laboratory, especially a detailed description of the composition of breast milk, its irreplaceable role in neonatal nutrition and description of breast milk processing in Milk Bank. This part is followed by a comprehensive chapter dealing with the treatment of the biological matrix before analysis. The most commonly used sample pretreatment techniques such as extraction methods are described here, with a great description of new trends in these...
Achiral and chiral high performance liquid chromatography of drugs and their metabolites III.
Horáček, Ondřej ; Nobilis, Milan (advisor) ; Mokrý, Milan (referee)
Nabumetone is non-steroidal anti-inflammatory prodrug that is converted into (6-methoxynaphthalen-2-yl)acetic acid in the liver. The differences of in vitro nabumetone biotransformation (rat vs human liver cytosolic and microsomal fractions) were studied in previous communication. Study of stereospecificity of enzymes and the calculation of enantiomeric ratios of the biotransformed chiral metabolites is an equally important characteristic of enzymes such as the Michaelis constant. Calculation of enantiomeric ratios of chiral metabolites biotransformed from prochiral drugs in vitro is used to identify new enzymes responsible for the biotransformation of a given prochiral drug. This work deals with the optimization of separation and detection conditions for achiral and chiral LLE-HPLC-PDA analysis of nabumetone and its six metabolites in extracts from various biomatrixes (human liver microsomal and cytosolic fractions and minipig blood plasma). Differences in biotransformation of nabumetone and racemic mixture of 3-HO-nabumetone between man and woman were studied in vitro in extracts from liver cytosolic and microsomal fractions, using chiral LLE-HPLC-PDA analysis. Enantiomeric ratios of all chiral metabolites of nabumetone were calculated. Pharmacokinetics of 6-MNA in minipig blood plasma after...
HPMC-based liposomal mucoadhesive films with model peptide as target API
Belcáková, Hedviga ; Nobilis, Milan (advisor) ; Doležal, Pavel (referee)
Charles University, Faculty of Pharmacy in Hradec Kralove Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Hedviga Belcáková Supervisor: Prof. Milan Nobilis, CSc., Veronika Fidelj (Heidelberg University, Insitute of Pharmacy and Molecular Biotechnology) Diploma thesis title: HPMC-based liposomal mucoadhesive films with model peptide as target API This thesis describes the preformulation stage of mucoadhesive films intended for liposomal peptide delivery via buccal membrane. The evaluation consisted of thickness, maximum tensile strength, strain, moisture content, in vitro swelling and liposome integrity measurements. The chosen polymer (hypromellose, HPMC) was found to perform optimally in concentrations of 10 % with PEG 400 (5 %) acting as plasticizer and liposome concentration of 2 %. The developed preparation method showed good reproducibilty with room for improvement in the homogenization area. The choice of medium (H2O vs. PBS) showed strong influence on formulation's mechanical properties resulting in significant loss of elasticity and mucoadhesive strength. The addition of liposomes in the third stage had been carried out successfully with only occassional effect on their integrity after dissolution.
Analytical evaluation of drugs using HPLC II.
Hanková, Eva ; Mokrý, Milan (advisor) ; Nobilis, Milan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Analysis Candidate: Eva Hanková Supervisor: RNDr. Milan Mokrý, CSc. Title of Diploma Thesis: Analytical evaluation of drugs using HPLC II. Abstract This diploma thesis dealt with analytical evaluation of tiaprofenic acid using high performance liquid chromatography. To determine tiaprofenic acid, a LiChroCART® 250-4 LiChrospher® 100 RP-18 (5 μm) column and a mobile phase consisting of acetonitrile and aqueous KH2PO4 buffer 0.01 mol/l in a ratio of 40 : 60 (v/v) were used. The pH of the buffer was adjusted to 3.0 with phosphoric acid; the flow rate was set to 1 ml/min and the temperature at 22 řC. Naproxen was chosen as the internal standard, and a 263 nm wavelength was used for detection. Since the tiaprofenic acid is a chiral substance present in the form of a racemate, the selection of chromatographic conditions for the separation of its enantiomers followed. Two chiral columns in both normal and reverse mode were tested. The cellulose-based Chiralcel OD-R 250 x 4.6 mm (10 μm) column was chosen as the most suitable, using a mobile phase of n-hexane : propan-2-ol : acetic acid in a ratio of 94 : 6 : 0,1 (v/v /v) at a flow rate of 0.5 ml/min and a temperature of 22 ř C. Enantiomers were eluted at...
The employment of HPLC in the field of chiral separations III.
Janetková, Monika ; Kučera, Radim (advisor) ; Nobilis, Milan (referee)
Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Faculty of Pharmacy in Hradec Králové, Charles University Candidate: Monika Janetková Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: doc. Ing. Radim Vespalec, DrSc. Title of Thesis: The employment of HPLC in the field of chiral separations III. Boron cluster compounds are completely synthetic inorganic structures posessing unique properties. Exceptional characteristics allow them to prove competent among organic molecules predominantely used in medicine. Basic structure is made of boron and hydrogen atoms forming three-dimensional polyhedron with triangular planes. The atoms B-H-B are forming electrondeficient three-centred two-electron bond. Cloud of electrons that is shared inside polyhedron structure is the cause of delocalized negative charge of a whole molecule. Boron cluster compounds are likely to loose hydrogen proton in both, protic and aprotic solvents, ending in formation of an anion. Among their typical characteristics belong extreme hydrophobicity, metabolic and thermal stability. Considering stability and reactivity closo-, nido- and arachno-clusters with 11-12 vertices are largely used. Either of endo- or exoskeletal substitution might impair symmetry of a boron cluster molecule resulting in a formation of...
Modern separation techniques for the analysis of biological material in clinical research
Kasalová, Eva ; Solich, Petr (advisor) ; Nobilis, Milan (referee) ; Friedecký, David (referee)
Charles University, Faculty of Pharmacy in Hradec Kralove Department of Analytical Chemistry Candidate: Mgr. Eva Kasalová Supervisor: Prof. RNDr. Petr Solich, CSc. Supervisor specialist: Assoc. Prof. RNDr. Dagmar Solichová, Ph.D. Title of Doctoral Thesis: Modern separation techniques for the analysis of biological material in clinical research This doctoral thesis deals with development and validation of a chromatographic determination of liposoluble vitamins and with optimization of biological materials preparation. Clinical monitoring of these vitamins, especially vitamin D in different biological materials is one of the most discuss theme in the last decade. In the theoretical part of this dissertation the target analytes - vitamins A, E and D with their biological activity are characterized - as well as the biological material used in the Research Laboratory, especially a detailed description of the composition of breast milk, its irreplaceable role in neonatal nutrition and description of breast milk processing in Milk Bank. This part is followed by a comprehensive chapter dealing with the treatment of the biological matrix before analysis. The most commonly used sample pretreatment techniques such as extraction methods are described here, with a great description of new trends in these...
The employment of HPLC in the field of chiral separations III.
Janetková, Monika ; Kučera, Radim (advisor) ; Nobilis, Milan (referee)
Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Faculty of Pharmacy in Hradec Králové, Charles University Candidate: Monika Janetková Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: doc. Ing. Radim Vespalec, DrSc. Title of Thesis: The employment of HPLC in the field of chiral separations III. Boron cluster compounds are completely synthetic inorganic structures posessing unique properties. Exceptional characteristics allow them to prove competent among organic molecules predominantely used in medicine. Basic structure is made of boron and hydrogen atoms forming three-dimensional polyhedron with triangular planes. The atoms B-H-B are forming electrondeficient three-centred two-electron bond. Cloud of electrons that is shared inside polyhedron structure is the cause of delocalized negative charge of a whole molecule. Boron cluster compounds are likely to loose hydrogen proton in both, protic and aprotic solvents, ending in formation of an anion. Among their typical characteristics belong extreme hydrophobicity, metabolic and thermal stability. Considering stability and reactivity closo-, nido- and arachno-clusters with 11-12 vertices are largely used. Either of endo- or exoskeletal substitution might impair symmetry of a boron cluster molecule resulting in a formation of...

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