National Repository of Grey Literature 225 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Supercritical fluids for extraction of biologically active compounds from Eucalyptus leaves
Herbsová, Diana ; Pilařová, Veronika (advisor) ; Sklenářová, Hana (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Diana Herbsová Supervisor: PharmDr. Veronika Pilařová, PhD. Title of the diploma thesis: Supercritical fluids for extraction of biologically active compounds from Eucalyptus leaves Eucalyptus is nowadays used for its anti-inflammatory, antibacterial, and antioxidant effects in the pharmaceutical and cosmetic industries. Eucalyptus contains various compounds including flavonoids, volatile compounds, terpenoid acids, and phenolic acids. The aim of this work was to develop a two-step selective extraction method for the extraction of compounds of different physicochemical properties from Corymbia citriodora leaves using extraction solvent containing CO2. Supercritical CO2 is a non-polar solvent with polarity and physicochemical properties, that can be changed by mixing with a suitable polar solvent. In this way, a wide range of compounds with different polarities can be extracted. In this study, the key parameters, including temperature in the range of 40-80 řC, pressure in the range of 100-300 bar were optimized using Box-Behnken design with heptane and ethanol/H2O as a cosolvent. After optimalization of the key parametres, the extraction kinetics were tested at flow rates of 2 mL/min and 4...
Monitoring of liberation tests for the release of clotrimazole from nanofibers
Ernest, Radovan ; Sklenářová, Hana (advisor) ; Chocholouš, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Kralove Department of Analytical Chemistry Candidate: Radovan Ernest Supervisor: Doc. PharmDr. Hana Sklenarova, Ph.D. Consultant: PhamDr. Martina Hakova, Ph.D. Title of the diploma thesis: Monitoring of liberation tests for the release of clotrimazole from nanofibers The diploma thesis was focused on the analysis of release profiles of clotrimazole from different types of nanofibres using non-separation flow technique, sequential injection analysis (SIA). Simultaneously the diploma thesis dealt with finding ideal conditions for saturation of the fibres with a solution of clotrimazole. Nanofibers were produced at the Technical university of Liberec. The diploma thesis dealt with two types of nanofiber carriers - polymeric (polydioxanone and polycaprolactone) and ceramic (silica). Part of the fibre of polydioxanone and polycaprolactone was saturated directly during production in different ratios of polymer and clotrimazole. The saturated fibres were then analysed in the laboratory. The second part of polydioxanone and polycaprolactone together with ceramic nanofibers was produced in a pure state, i.e., without an active substance. These fibres were tested in the laboratory for saturation with an ethanolic solution of clotrimazole at a certain...
Development of UHPLC-DAD method for separation of phenolic substances in plant material and extraction optimization
Turčanová, Anna ; Sklenářová, Hana (advisor) ; Šatínský, Dalibor (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Anna Turčanová Supervisor: doc. PharmDr. Hana Sklenářová, Ph.D. Advisor: Mgr. Marcela Hollá Title of the diploma thesis: Development of UHPLC-DAD method for separation of phenolic substances in plant material and extraction optimization This diploma thesis deals with development of UHPLC-DAD method for separation of selected phenolic substances (arbutin, chlorogenic, neochlorogenic, cryptochlorogenic, isochlorogenic A and caffeic acid, cynarin, catechin, epicatechin, rutin, hyperoside, hirsutrin, reynoutrin, guaiaverin, quercitrin and quercetin). UHPLC analysis of these phenolic substances took place on a Luna® Omega Polar C18 100 (150 x 2.1 mm; 1.6 μm) column with fully porous particles. As a part of the optimization method, a column with core-shell particles (Kinetex® Polar C18) and a column with a hybrid stationary phase (YMC-Triart C18 ExRS) were also tested. The sample injection volume was 2 μl, the flow rate has been set to 0.3 ml/min and temperature of the column has been set to 30 řC. As a mobile phase ultrapure water acidified with acetic acid to pH 2.8 in combination with acetonitrile has been used. The total analysis time was 17.5 min and detection was performed using a DAD detector at...
Automation of liberation tests for clotrimazole released from differently saturated polymer nanofibers
Mukařovská, Sabina ; Sklenářová, Hana (advisor) ; Chocholouš, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of analytical chemistry Candidate: Sabina Mukařovská Supervisor: doc. PharmDr. Hana Sklenářová, Ph.D. Title of the diploma thesis: Automation of liberation tests for clotrimazole released from differently saturated polymer nanofibers This diploma thesis deals with the liberation profiles of clotrimazole released from a nanofiber carrier using an automated non-separation flow technique, sequential injection analysis. Polymer nanofibers polydioxanone and polycaprolactone were chosen as membranes. Nanofiber membranes were manufactured by the Technical University of Liberec. Two nanofiber saturation procedures were successively tested. First, membranes were used which were saturated during production in different ratios of polymer and clotrimazole content. These fiberes were analysed in the laboratory. In the second part, the fiberes without the active substance were tested, it means they originally did not contain clotrimazole. The nanofiber membranes thus prepared were saturated with ethanolic solutions of various concentrations and for a certain period of time in laboratory conditions. These analyses helped to find ideal conditions for nanofiber saturation. Liberation tests were performed under conditions that simulated the...
The effect of chitosan as excipient on dissolution of meloxicam
Machová, Barbora ; Matysová, Ludmila (advisor) ; Sklenářová, Hana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Barbora Machová Supervisor: doc. PharmDr. Ludmila Matysová, Ph.D. Consultant: Mgr. Jana Brokešová Title of the diploma thesis: The effect of chitosan as excipient on dissolution of meloxicam. The main objective of this diploma thesis was to develop a suitable dissolution method for evaluating the release of meloxicam from capsules and subsequently determining the effect of chitosan as excipient on the dissolution of this drug. The influence of preparation method of mixture in the capsules was also monitored. The mixture consisted of combination meloxicam with chitosan (MX-CH) in a ratio of 1:8, which was prepared by mixing in a Turbula 3D instrument, or by grinding using a planetary ball mill for 5 or 30 minutes. The dissolution was performed in a dissolution device with a paddle. The phosphate buffer with a pH of 6,8 was selected as a medium. Four formulations were tested including capsules filled with drug only and capsules filled with the mentioned mixture (MX-CH). Samples were gradually collected at time intervals and then measured with UV/VIS spectrophotometer. Based on the measured and calculated values, it is clear, that the excipient chitosan helped to better and faster release of...
Vývoj nové pyruvát-selektivní elektrody pro kontrolu kvality vína
Zelená, Lucie ; Solich, Petr (advisor) ; Sklenářová, Hana (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Lucie Zelená Supervisors: Prof. Maria da Conceição Branco da Silva, Dr. Célia Maria Pinto Gomes Amorim; Department of Analytical chemistry, Faculty of Pharmacy, University of Porto. Prof. RNDr. Petr Solich, CSc; Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague. Title of master's thesis: Development of a new pyruvate-selective electrode for wine control Pyruvate and other organic acids can influence the properties of wines as for example flavor, color, aroma or stability. New fast, low-cost, simple and sensitive methods have been developed for wine quality control. A development of a new selective electrode for potentiometric determination of pyruvate in wine samples was the aim of this work. Sensors based on PVC membrane using 5,10,15,20-Tetraphenyl-21H,23H-porphine manganese (III) chloride as ionophore were under study. Several solvent mediators and lipophilic additives were tested in optimization of response characteristics of sensors. The most interesting response showed membrane with 2-Nitrophenyl phenyl ether as a solvent mediator and Potassium tetrakis(2-chlorophenyl)borate as a lipophilic additive. Sensors with the best characteristics are...
Sequential injection analysis BI-LOV - development of technique for sample treatment using solid phase extraction I
Popovská, Lenka ; Chocholouš, Petr (advisor) ; Sklenářová, Hana (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical chemistry Candidate: Mgr. Lenka Popovská Supervisor: PharmDr. Petr Chocholouš, Ph.D. Title of diploma thesis: Sequential injection analysis BI - LOV - development of technique for sample treatment using solid phase extraction I Antioxidant activity of polyphenolic compounds can positively affect the therapy and the prevention of diseases associated with oxidative stress, e.g. cardiovascular diseases, atherosclerosis, neurodegenerative diseases (Alzheimer's and Parkinson's diseases), rheumatoid arthritis, virus diseases, neoplasms, benign prostatic hyperplasia (BHP), prostatitis etc. This diploma thesis deals with the analysis of phenolic acids, namely ferulic acid and also protocatechuic acid and o-coumaric acid. The ferulic acid was analysed within five concentrations (10,000 µg/ml, 5,000 µg/ml, 2,500 µg/ml, 1,250 µg/ml and 0,625 µg/ml), four different strong anion exchangers (TMAHP, QAE - A25, SAX - BOND and SAX - DSC), five different pH (5,0, 6,0, 7,0 a 8,5) of washing buffer and three different pH (1,5, 2,0 a 2,5) of elution buffer. Absorbance of the ferulic acid was measured at wavelengths 325 and 240 nm. In this thesis was also assessed handling with each sorbent, especially convenient use within LOV...
Sequential injection chromatography-testing and comparison of modern chromatographic columns
Molnárová, Petra ; Chocholouš, Petr (advisor) ; Sklenářová, Hana (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Deparment of Analytical chemismy Candidate: Bc. Petra Molnárová Supervisor: PharmDr. Petr Chocholouš, PhD. Title of diploma thesis: Sequential injection chromatogramy - testing and comparison of modern chromatographic columns This diploma thesis deals with testing and comparison of two modern chromatoghraphic columns in Sequential injection chromatography system. They were used for separation of selected vitamins B (thiamine, nikotinamide, pyridoxine, riboflavin and folic acid) and vitamin C. Developed method was based on UV detection at 220, 272 and 290nm. The Ascentis Express HILIC column (3 cm x 4.6 mm, 2.7 µm) was tested by using acetonitrile with ammonium acetate as a mobile phase. The method was not siccessfully developed because of low retention times of vitamins. The separation of six vitamins was not able, because of low selectivity. There was developed a method with use of Ascentis Express RP- Amide column (3 cm x 4.6 mm, 2.7 µm) using gradient elution, which was able to separate all 6 vitamins. Acetonitrile and phosphoric acid (pH 1.8) were components of the mobile phases. There was made calibration, reproducibility and recovery tests, but there was not good results enough to validate the method. For recovery was used...
Development and validation of method for determination of furosemide and its degradation product in pharmaceutical formulations
Břežná, Tereza ; Matysová, Ludmila (advisor) ; Sklenářová, Hana (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Tereza Břežná Advisor: PharmDr. Ludmila Matysová, Ph.D. Thesis name: Development and validation of method for determination of furosemide and its degradation product in pharmaceutical formulations This thesis is focused on development and validation of a method for determination of furosemide and its degradation product in pharmaceutical formulations. The development was based on the HPLC method, which uses the mixture of 0.1 % formic acid and methanol in the 30:70 ratio as the mobile phase. The method development has been namely based on the mobile phase composition and analysis temperature conditions optimizing. In the final version was used the HPLC method with UV-VIS detection at 270 nm. The analysis was performed at the laboratory temperature using isocratic elution and C18 15 x 4.6 mm column with 5 μm particle size. The mixture of pH 5.75 formic acid and acetonitrile in the 65:35 ratio and at 1.5 ml/min flow rate has been selected as the mobile phase. The validation has proven that this method provides precise and acurate results and therefore it is suitable for furosemide determination in the solutions of medicinal products.

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