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Optimization and validation of analytical method for determination of selected drugs
Geryk, Radim ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The aim of this work was finding suitable conditions for separation of enantiomers of citalopram and citadiol, optimization of chromatographic system and validation of the analytical method for determination of selected enantiomers in drugs. Drugs are often chiral compounds. In many cases, only enantiomer has required pharmacological effects. Advanced chemical technologies associated with the synthesis, separation and analysis of the individual enantiomers caused an increase of the number of new chiral drugs in the form of single pure enantiomers, the chiral switch. Citalopram is one of the widely used antidepressants of selective serotonin reuptake inhibitors (SSRI). Citalopram is used for treatment of depression, panic anxienty or obsessive compulsive disorder of pathological laughing and crying. The pharmacological activity is associated with the S-citalopram, while R-enantiomer is essentially inactive and even counteracts the activity of escitalopram. Citadiol is a chiral syntetic precursor of citalopram. This thesis was focused on monitoring enantioseparation "behaviour" of selected enantiomers. HPLC method with chiral stationary phases based on macrocyclic antibiotics, cyclofructans and cellulose was applied for enantioseparation of the above-mentioned compounds. The optimized chromatographic...
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Determination of enantiomers of selected drugs by HPLC
Geryk, Radim ; Tesařová, Eva (advisor) ; Chudoba, Richard (referee)
Drugs are often chiral compounds. In many cases only one of the enantiomers has required therapeutical effects. Citalopram belongs to a group of chiral drugs. This drug is used as an antidepresivum for treating anxiety, fear or suppressing of pain feeling. Its synthetical precursor is named citadiol and this compound is also chiral. HPLC method with chiral stationary phases based on macrocyclic antibiotics was applied for enantioseparation of above-mentioned compounds. Polar-organic and ionic-polar separation modes were found to be suitable for chiral separation of citalopram and citadiol enantiomers. The aim of this work was monitoring of enantioseparation "behaviour" of selected enantiomers and to find suitable separations conditions using HPLC method.
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Complex equilibriums of beta-blockers in CZE
Kanizsová, Lívia
Drugs used in the pharmaceutical industry often occur as a mixture of several isomers with a different biological activity. In a case that some isomer provides an undesirable side effect, it is important to separate it from the mixture and check the chiral purity of a drug. Capillary zone electrophoresis plays a significant role in chiral separations. A different affinity of isomers to complexation reagent is used for their separation from each other. The extent of their interaction is characterized by the complexation constant. Most commonly the cyclodextrins are used for the chiral separations of β-blockers and they could be in neutral or charged form. They probably interact with them through the creation of inclusion complexes. A successful baseline enantioseparation of all the β-blockers that have been studied, labetalol, pindolol, alprenolol and atenolol, was provided by using the background electrolyte containing charged cyclodextrins. The highest resolution of peaks was observed using sulfated cyclodextrins.
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Separation of chiral compounds
Šrolerová, Tereza ; Kubíčková, Anna (advisor) ; Křížek, Tomáš (referee)
This bachelor thesis deals with the chiral separation of newly synthesized orthoconic antiferroelectric liquid crystals using ultra-high performance liquid chromatography. These studied compounds differ in the alkyloxy-spacer length, in the presence and/or position of the fluorine atom on the phenyl ring and in the chiral center. The separation took place in a reverse separation mode using a chiral stationary phase based on derivatized amylose. First, the effect of mobile phase flow rate and column temperature on separation efficiency was exanimated. The effect of the composition of the mobile phase on the enantioseparation were studied at the optimum temperature and flow rate. The mobile phase was based on acetonitril, while deionized water was added gradually using isocratic elution. Furthermore, the effect of chromatographic conditions and the structure of the studied analytes on resolution and enantioselectivity was investigated, concretely the presence and position of fluorine atom on pfenyl ring, the length of alkyloxy-spacer and the effect of divergent chiral center. Under optimized chromatography conditions we succeeded to separate all examined substances on the base line. Key words: ultra-high performance chromatography, liquid crystals, enantioseparation, chiral stationary phase, reverse mode
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Chiral separations of orthoconic antiferroelectric liquid crystals
Archuleta, Natália ; Kubíčková, Anna (advisor) ; Kozlík, Petr (referee)
This study reports chiral separation of orthoconic antiferroelectric liquid crystals using ultra-high performance liquid chromatography. The materials studied in this paper differ in the presence and/or position of the fluorine atom on the phenyl ring and in the alkoxy-spacer length. Reversed non-aqueous mode using chiral stationary phase based on derived polysaccharides was used. In the first part of the thesis, the effect of the mobile phase flow rate and the column temperature on the enantioseparation efficiency was observed. Subsequently, under optimum flow rate and column temperature, the effect of mobile phase composition was examined. The mobile phase was based on acetonitrile, while various ratios of methanol, ethanol or isopropanol were added using isocratic elution. Two chromatographic columns containing different chiral stationary phase were compared - CHIRALPAK® IA-U amylose tris(3,5-dimethylphenylcarbamate) and CHIRALPAK® IG-U amylose tris(3-chloro-5-methylphenylcarmabate). We studied the influence of chromatographic conditions and analyte structure on resolution, enantioselectivity and retention. Key words: ultra-high performance liquid chromatography, enantioseparation, liquid crystals, reversed phase
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Complex equilibriums of beta-blockers in CZE
Kanizsová, Lívia
Drugs used in the pharmaceutical industry often occur as a mixture of several isomers with a different biological activity. In a case that some isomer provides an undesirable side effect, it is important to separate it from the mixture and check the chiral purity of a drug. Capillary zone electrophoresis plays a significant role in chiral separations. A different affinity of isomers to complexation reagent is used for their separation from each other. The extent of their interaction is characterized by the complexation constant. Most commonly the cyclodextrins are used for the chiral separations of β-blockers and they could be in neutral or charged form. They probably interact with them through the creation of inclusion complexes. A successful baseline enantioseparation of all the β-blockers that have been studied, labetalol, pindolol, alprenolol and atenolol, was provided by using the background electrolyte containing charged cyclodextrins. The highest resolution of peaks was observed using sulfated cyclodextrins.
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Complex equilibriums of beta-blockers in CZE
Kanizsová, Lívia ; Zusková, Iva (advisor) ; Jelínek, Ivan (referee)
Drugs used in the pharmaceutical industry often occur as a mixture of several isomers with a different biological activity. In a case that some isomer provides an undesirable side effect, it is important to separate it from the mixture and check the chiral purity of a drug. Capillary zone electrophoresis plays a significant role in chiral separations. A different affinity of isomers to complexation reagent is used for their separation from each other. The extent of their interaction is characterized by the complexation constant. Most commonly the cyclodextrins are used for the chiral separations of β-blockers and they could be in neutral or charged form. They probably interact with them through the creation of inclusion complexes. A successful baseline enantioseparation of all the β-blockers that have been studied, labetalol, pindolol, alprenolol and atenolol, was provided by using the background electrolyte containing charged cyclodextrins. The highest resolution of peaks was observed using sulfated cyclodextrins.
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