National Repository of Grey Literature 51 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Evaluation of biologically active substances using HPLC IV.
Seidlová, Martina ; Pilařová, Pavla (advisor) ; Nobilis, Milan (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department Pharmaceutical Chemistry and Drug Kontrol Name of Degrese Paper: Evaluating of biologically active substances by HPLC IV. Candidate: Martina Seidlová Tutor: PharmDr. Pavla Pilařová, Ph.D. In this diploma work the study of dilation behaviour of medications was provided under extreme conditions for a column being able to measure pH ranged 1-12 on column Kinetex EVO C18 (150 x 3 mm). For higher pH the following medications were studied: quetiapine, and its two metabolites - norquetiapine and 7-hydroxyquetiapine, bromhexine, codeine, zolpidem and its admixture, fluoxetine and aciclovir. The best results were reached with quetiapine with its metabolites, therefore they were chosen for the following tests and possibility of separation from plasma. As a mobile phase an acidic buffer was used at pH10 using ratio 70:30 to organic phase which was made of acetonitrile and methanol (55:5). For lower pH the following medications were studied: salicylic acid, acetylsalicylic acid, aciclovir, bromhexine and fluoxetine. The best results were reached with salicylic acid and acetylsalicylic acid, therefore they were chosen for the following testing and the possibility of separation in the medicament. As a mobile phase a phosphate buffer...
Study of chiral aspects of drug metabolism using instrumental analytic methods
Holmanová, Veronika ; Nobilis, Milan (advisor) ; Kovaříková, Petra (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Candidate: Bc. Veronika Holmanová Supervisor: Doc. PharmDr. Milan Nobilis, CSc. Title of diploma thesis: Study of chiral aspects of drug metabolism using instrumental analytic methods For the evaluation of stereospecificity of rat and human cytosolic carbonyl reductases and activity of microsomal oxidases involved in nabumetone biotransformation, a new chiral high-performance liquid chromatographic method was developed. The prepared LLE-HPLC-PDA method enabled extraction, separation and ultraviolet detection of prochiral nabumetone and its five phase I metabolites including enantiomers of two chiral biotransformation products of carbonyl reduction. Methyl ester of naproxen served as an internal standard. Diethyl ether was used for liquid-liquid extraction (LLE) of biomatrices. Chiralcel OD-R 250 mm×4.6 mm column with a mobile phase methanol-1M NaClO4/HClO4 aqueous solution pH=3 (75:25, v/v) were employed in isocratic sufficient separation of nine analytes. The whole analysis lasted 60 minutes at the flow rate of 0.5 ml/min. The column effluent was monitored using a photodiode-array detector (scan or single wavelength at λ=265 nm). The results of in vitro nabumetone...
Vliv vybraných látek ovlivňujících centrální nervový systém na kostní metabolismus
Fekete, Soňa ; Živný, Pavel (advisor) ; Horák, Pavel (referee) ; Nobilis, Milan (referee)
The increase in life expectancy of the world population is associated with challenges regarding health issues. For instance, osteoporosis is a medical condition mostly observed in elderly people, in which the quality and quantity of the bone are severely affected. Not only for women but also for men, osteoporosis is recognized as an important public health issue. Osteoporosis is a systemic skeletal disorder and is a result of loss of skeletal mass. Osteoporosis is characterized by low bone mass, microarchitectural deterioration of bone tissue and an increase in bone fragility and susceptibility to fracture. Osteoporotic fractures are a significant cause of morbidity and mortality. The longterm use of drugs such as antiepileptics and antidepressants could affect the onset of osteoporosis. The aim of the study was to evaluate the effect of orchidectomy, the effect of newer antiepileptic (levetiracetam, lacosamide, topiramat, lamotrigine) and antidepressive drugs (mirtazapine, venlafaxine and trazodone) on bone metabolism in healthy male Wistar rats. The first specific aim was to determine the effect of orchidectomy on bone metabolism in rats. We found that after 12 weeks post-orchidectomy there was a negative effect on bone metabolism in rats. These results established these animals as suitable models for...
Vliv vybraných látek ovlivňujících centrální nervový systém na kostní metabolismus
Fekete, Soňa ; Živný, Pavel (advisor) ; Horák, Petr (referee) ; Nobilis, Milan (referee)
The increase in life expectancy of the world population is associated with challenges regarding health issues. For instance, osteoporosis is a medical condition mostly observed in elderly people, in which the quality and quantity of the bone are severely affected. Not only for women but also for men, osteoporosis is recognized as an important public health issue. Osteoporosis is a systemic skeletal disorder and is a result of loss of skeletal mass. Osteoporosis is characterized by low bone mass, microarchitectural deterioration of bone tissue and an increase in bone fragility and susceptibility to fracture. Osteoporotic fractures are a significant cause of morbidity and mortality. The longterm use of drugs such as antiepileptics and antidepressants could affect the onset of osteoporosis. The aim of the study was to evaluate the effect of orchidectomy, the effect of newer antiepileptic (levetiracetam, lacosamide, topiramat, lamotrigine) and antidepressive drugs (mirtazapine, venlafaxine and trazodone) on bone metabolism in healthy male Wistar rats. The first specific aim was to determine the effect of orchidectomy on bone metabolism in rats. We found that after 12 weeks post-orchidectomy there was a negative effect on bone metabolism in rats. These results established these animals as suitable models for...
Development and Validation of HPLC Methods for Transport and Metabolic Studies
Hroch, Miloš ; Nobilis, Milan (advisor) ; Šatínský, Dalibor (referee) ; Šišpera, Luděk (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Candidate Ing. Miloš Hroch Consultant Doc. PharmDr. Milan Nobilis, CSc. Title of Thesis Development and validation of HPLC methods for transport and metabolic studies The presented PhD thesis deals with the development and validation of chromatographic methods in bioanalysis of drugs and their metabolites. The work provides a theoretical introduction to the field of bioanalysis, using methods of liquid chromatography. Attention was paid to recent trends in the area, particularly with respect to the new types of stationary phases. In the experimental part of the thesis, reader is introduced to a development and validation of several bio-analytical methods using high performance liquid chromatography. The first method concerns with a determination of 5-fluorouracil and its metabolites by HPLC with gradient elution and UV/VIS detection on a column Luna PFP (2). Discussed are mainly specifics for the assay of this group of polar and poorly detectable compounds. The developed and validated method is being used for TDM of patients with rectal cancer. Another discussed method deals with a determination of methotrexate polyglutamates in erythrocytes using isocratic elution on a hybrid...
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.
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...
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...

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