National Repository of Grey Literature 14 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Usage of flow through cell dissolution method for medical preparations with controlled release
Milerová, Romana ; Rabišková, Miloslava (advisor) ; Vraníková, Barbora (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: prof. PharmDr. Miloslava Rabišková, CSc. Student: Romana Milerová Title of Thesis: Usage of flow through cell dissolution method for medical preparations with controlled release Dissolution studies are a very effective tool for easy and efficient obtaining information about the behavior of medical preparations in the human body. For decades, it has been successfully used in the development of dosage forms as well as in quality control for batch quality control during routine production. In vitro dissolution testing has become even more important because the in vitro/ in vivo correlation is based on their results. This diploma thesis presents the usage of flow through cell dissolution method for medical preparations with controlled release. This work describes both the specific description of the flow thorough cell method and the test methods specified in the Czech Pharmacopoeia which uses it. Next, follows a breakdown according to the dosage forms together with a description of the modification of the flow through methods. Since the flow through cell was originally designed for oral controlled release drug formulations, the most extensive part of the work is focused on this route of...
Clay minerals as drug stabilizers
Markytánová, Petra ; Rabišková, Miloslava (advisor) ; Vraníková, Barbora (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Farmaceutické technologie Consultant: prof. PharmDr. Miloslava Rabišková, CSc. Student: Petra Markytánová Title of Thesis: Clay minerals as drug stabilizers This thesis presents clay minerals as drug stabilizers. The aim of thesis was introduction of phyllosilicates, kaolinite, talc, smectites and fibrous clays which belong to the most important minerals. These clays are widely used as active substances or excipients in the formulation of dosage forms such as solid, liquid or semisolid. The structure, classification and useful properties directly related to their colloidal size and structure are shortly disscussed. Clay minerals posses excellent properties such as high adsorption capacity, swellability, low or null toxicity, good biokompatibility and promise for controlled release, thus give rise to the incess and interest to their development for biological purposes. The important chapter are current challenges in pharmaceutical applications. Besides classic pharmaceutical uses, clay minerals may be effectively used in formulations for controlled drug delivery systems. A very interesting possibility is to use clay minerals polymer composites, that can be used to prepare the nanoparticles, films, hydrogels or...
Influence of lubricants on viscoelastic parameters of compaction process
Svačinová, Petra ; Rabišková, Miloslava (advisor) ; Kubová, Kateřina (referee) ; Zámostný, Petr (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department Pharmaceutical technology Candidate Mgr. Petra Svačinová Supervisor Prof. PharmDr. Miloslava Rabišková, CSc. Title of Doctoral Thesis Influence of lubricants on viscoelastic parameters of compaction process This thesis deals with an evaluation of lubricant's influence on viscoelastic parameters of compaction process. The force-displacement record and stress relaxation test were used for this evaluation. This study evaluates the viscoelastic parameters on three fillers intended for direct compression, i.e. microcrystalline cellulose Avicel PH-200, lactose Lactochem Fine Crystals and calcium hydrogen phosphate dihydrate Emcompress. Magnesium stearate and modified colloidal silica Syloid were used as lubricants at concentrations of 0.5 % and 1 %. Particle size and shape and specific surface area were determined for all used excipients. Flow properties were studied for individual fillers and also for their mixtures with lubricants. Subsequently, tablets were compressed from fillers and mixtures using force-displacement record and stress relaxation test, and viscoelastic parameters were evaluated. The applied compression forces for both methods were 5 kN, 10 kN and 15 kN. The hardness of tablets was measured. The results show...
Evaluation of the influence of filler sort and lubricant type and concentration on the parameters of the compaction equation
Ondrejček, Pavel ; Rabišková, Miloslava (advisor) ; Vetchý, David (referee) ; Bělohlav, Zdeněk (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Department of pharmaceutical technology Candidate Mgr. Pavel Ondrejček Supervisor prof. PharmDr. Miloslava Rabišková, CSc. Title of Doctoral Thesis Evaluation of the influence of filler sort and lubricant type and concentration on the parameters of the compaction equation This thesis is dealing with an evaluation of the compaction process of pharmaceutical excipients and their mixtures. The effect of the filler type, lubricant type and its concentration on the parameters of the compaction equation developed by Assoc. Prof. RNDr. Milan Řehula, CSc. is studied. Microcrystalline cellulose Avicel PH-200, lactose Lactochem Fine Crystals and calcium hydrogen phosphate dihydrate Emcompress were used as model fillers. These fillers of similar particle size were selected because of different bonding mechanism and varying course of the compaction process. Fillers were evaluated individually and then in their blends with lubricants magnesium stearate, sodium stearylfumarate and Syloid, i.e. modified colloidal silica in concentration 0,5 and 1 %. Moisture content and flow properties were determined in individual fillers. Particle size distribution, scanning electron microscope pictures and specific surface area measurements were...
Influence of lubricants on viscoelastic parameters of compaction process
Svačinová, Petra ; Rabišková, Miloslava (advisor) ; Kubová, Kateřina (referee) ; Zámostný, Petr (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department Pharmaceutical technology Candidate Mgr. Petra Svačinová Supervisor Prof. PharmDr. Miloslava Rabišková, CSc. Title of Doctoral Thesis Influence of lubricants on viscoelastic parameters of compaction process This thesis deals with an evaluation of lubricant's influence on viscoelastic parameters of compaction process. The force-displacement record and stress relaxation test were used for this evaluation. This study evaluates the viscoelastic parameters on three fillers intended for direct compression, i.e. microcrystalline cellulose Avicel PH-200, lactose Lactochem Fine Crystals and calcium hydrogen phosphate dihydrate Emcompress. Magnesium stearate and modified colloidal silica Syloid were used as lubricants at concentrations of 0.5 % and 1 %. Particle size and shape and specific surface area were determined for all used excipients. Flow properties were studied for individual fillers and also for their mixtures with lubricants. Subsequently, tablets were compressed from fillers and mixtures using force-displacement record and stress relaxation test, and viscoelastic parameters were evaluated. The applied compression forces for both methods were 5 kN, 10 kN and 15 kN. The hardness of tablets was measured. The results show...
Evaluation of the influence of filler sort and lubricant type and concentration on the parameters of the compaction equation
Ondrejček, Pavel ; Rabišková, Miloslava (advisor) ; Vetchý, David (referee) ; Bělohlav, Zdeněk (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Department of pharmaceutical technology Candidate Mgr. Pavel Ondrejček Supervisor prof. PharmDr. Miloslava Rabišková, CSc. Title of Doctoral Thesis Evaluation of the influence of filler sort and lubricant type and concentration on the parameters of the compaction equation This thesis is dealing with an evaluation of the compaction process of pharmaceutical excipients and their mixtures. The effect of the filler type, lubricant type and its concentration on the parameters of the compaction equation developed by Assoc. Prof. RNDr. Milan Řehula, CSc. is studied. Microcrystalline cellulose Avicel PH-200, lactose Lactochem Fine Crystals and calcium hydrogen phosphate dihydrate Emcompress were used as model fillers. These fillers of similar particle size were selected because of different bonding mechanism and varying course of the compaction process. Fillers were evaluated individually and then in their blends with lubricants magnesium stearate, sodium stearylfumarate and Syloid, i.e. modified colloidal silica in concentration 0,5 and 1 %. Moisture content and flow properties were determined in individual fillers. Particle size distribution, scanning electron microscope pictures and specific surface area measurements were...
Possibilities for in-vitro testing of controlled-release parenterals.
Kožák, Jan ; Řehula, Milan (advisor) ; Rabišková, Miloslava (referee)
The objective of this study was to start with the development of a gel-based medium simulating intramuscular environment for in-vitro drug release testing as an alternative to currently used water-based media. A pork meat was selected as a model of the muscle tissue. At the first part of the study, diffusion rate was proposed as the most determining factor of drug release in gel-based medium. Consequently, the diffusion rate of sodium fluorescein in pork meat was compared with the diffusion rate in various gels, namely gelatine, calcium alginate and different grades of hydroxypropyl methylcellulose (HPMC). The measurments were performed at 37řC with respect to recomendations for drug dissolution testing and in- vivo temperature. Gelatine however underwent a gel-sol transition at 37řC regardless to polymer concentration and showed to be unsuitable for measurement by selected method. The diffusion rate of fluorescein in all used gels was higher than the diffusion rate in the meat. Only 25% HPMC (Methocel E4M grade) showed acceptable similarity to meat, in terms of the diffusion rate, and was consequently selected for the second part of the study. In the second part of the study, the release of ibuprofen from ethylcellulose implants (ethylcelulose : ibuprofen weight ratio 9:1) in pork meat and 25%...
Effect of Amino Acids Derivatives And Ceramides on Skin Barrier Function
Janůšová, Barbora ; Vávrová, Kateřina (advisor) ; Balgavý, Pavol (referee) ; Rabišková, Miloslava (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of inorganic and organic chemistry Candidate: Mgr. Barbora Janůšová Supervisor: doc. PharmDr. Kateřina Vávrová, Ph.D. Title of Doctoral Thesis: Effect of amino acids derivatives and ceramides on skin barrier function The main goal of my thesis was to contribute to the understanding of behavior of the ceramides and skin barrier function modulators based on amino acids derivatives, as well as to elucidate the relationship between their structure and activity. Transdermal permeation enhancers are compounds that temporarily decrease skin barrier properties to promote drug flux. In the first part of my thesis, enhancers with amino acids (proline, sarcosine, alanine, β-alanine, and glycine) attached to hydrophobic chain(s) via a biodegradable ester link were investigated. The double-chain lipid-like substances displayed no enhancing effect, whereas single-chain substances significantly increased skin permeability. The most active enhancer - proline derivative L-Pro2 reached enhancement ratios of up to 40 at 1% concentration, which is higher than that of the well-established and standard enhancers Azone, DDAIP, DDAK, and Transkarbam 12. No stereoselectivity was observed. L-Pro2 acted synergistically with propylene glycol and...
Study of water-absorption of nanofibres made from hyaluronate derivatives.
Lebedová, Václava ; Šklubalová, Zdeňka (advisor) ; Rabišková, Miloslava (referee)
Charles University in Prague, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical technology Consultant: Doc. PharmDr. Zdeňka Šklubalová, Ph.D. Ing. Jana Růžičková, Ph.D. Student: Václava Lebedová Title of Thesis: Study of water-absorption of nanofibres made from hyaluronate derivatives Micro and nanofibers have suitable properties to be used as dressing in healing of injuries. In this experimental work, I studied the properties of nanofibres made from new synthesized hyaluronate derivates (HA). The nanofibres were manufactured by electrospinning method using model version of 4SPIN. To modify properties of the aqueous solutions of HA, polyethylene oxide 400 000 was used. The resulting solutions had an appropriate surface tension, conductivity, and viscosity required to prepare nanofibres. The samples of nanofibres were crosslinked by UV radiation for 10 minutes (HA10) and/or 60 minutes (HA60). To study the influence of crosslinking on the sorption capacity of nanofibres, the free swell absorbency method was used in which samples were immersed in a bath containing water and/or a 0,9% aqueous solution of sodium chloride, respectively, for 5 minutes (liquor/fibre ratio of 75:1). The nanofibers crosslinked for 60 minutes had significantly larger absorbency of both liquid media than...
Transdermal Permeation Enhancers: Study of Structure-activity Relationships.
Novotný, Michal ; Vávrová, Kateřina (advisor) ; Nobilis, Milan (referee) ; Rabišková, Miloslava (referee)
Permeation enhancers are compounds that promote drug flux into systemic circulation or adjacent tissues. This doctoral thesis follows our previous results and aims at studying two different groups of potential permeation enhancers: dicarboxylic acid derivatives and analogues of Transkarbam 12. The main purpose of my work was to study the structure- activity relationships in these permeation enhancers and to contribute to the elucidatation of their mechanism of action. The first part of my work was focused on derivatives of dicarboxylic acids. Series of enhancers based on maleic, fumaric, succinic, tartaric and meso-tartaric acids were prepared. The enhancing activity of these compounds was investigated in vitro in Franz diffusion cells using theophylline as a model drug and porcine skin. The single-chain amphiphiles were markedly more effective than the double-chain ones. The most active enhancer, monododecyl maleate, that is a cis- derivative, was a more potent enhancer than its respective trans- isomer. Furthermore, the activity of similar succinates, i.e. compounds having a single bond, strongly depended on the donor vehicle. No difference between diastereoisomeric tartaric and meso-tartaric acid derivatives was found. The second part of my work dealt with Transkarbam 12, an ammonium carbamate...

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