|
|
Evaluation of compressibility of tableting mixtures containing different amount of sodium stearyl fumarate
Chrzová, Iryna ; Svačinová, Petra (advisor) ; Vraníková, Barbora (referee)
Charles University, Faculty of Pharmacy in Hradec Králové This thesis deals with the evaluation of the compressibility of tablets with different content of sodium stearyl fumarate (SSF). A mixture of microcrystalline cellulose and lactose in a 1:1 ratio was used as a model substance. The glidant sodium stearyl fumarate was added at concentrations of 0.5%, 1%, 1.5% and 2%. Subsequently, the tablets were pressed at a compression force of 5 kN, 7 kN and 10 kN using force- displacement record. The energy profile of the compression process was recorded, and the ejection force was also evaluated. Then crushing force, disintegration time, friability and true density were measured. The values of tensile strength, porosity, axial and volume relaxation characterizing the properties of prepared tablets were calculated from the obtained results. During the evaluation of the energy profile, it emerged that E1, E2, E3, Elis and Emax increase with increasing pressing force. The addition of SSF has minimal effect on the energy profile. At a concentration of 0.5% and 1% of SSF, the highest axial relaxation was measured, concentrations of 1.5% and 2% had no effect on the relaxation of the tablets. A decrease in volume relaxation occurred at all compression forces and concentrations of SSF. The most significant...
|
|
|
Interaction of PAMAM dendrimers with the human stratum corneum
Žofková, Kateřina ; Paraskevopoulou, Anna (advisor) ; Svačinová, Petra (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Supervisor: PharmDr. Anna Paraskevopoulou, Ph.D. Author: Kateřina Žofková Title of the thesis: Interaction of PAMAM dendrimers with human stratum corneum Dendrimers are highly branched, monodisperse macromolecules. On the basis of the degree of branching, can be distinguished different generations of dendrimers that arise as the dendrimers expand. Higher generations of dendrimers form spherical structures with an internal cavity, where molecules such as a drug can be encapsulated. Due to their structure, which can be specifically and controllably modified, dendrimers are investigated for their use in biomedicine. One of the most widely used groups of dendrimers are polyamidoamine (PAMAM) dendrimers, based on an ethylenediamine core, branched amide and amine units, and terminal functional groups. PAMAM dendrimers with amine groups have proven useful in the past as skin penetration enhancers of different drugs. However, the mechanism how these molecules affect skin barrier function is not yet known. Therefore, in this work was investigated the mechanism of interaction of PAMAM dendrimers with lipids of stratum corneum (SC), the uppermost skin layer where the skin barrier is found. Second, third and...
|
|
|
Development of a new model for the evaluation of compression phase of compaction process
Grande, Vojtěch ; Ondrejček, Pavel (advisor) ; Svačinová, Petra (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of Pharmaceutical Technology Consultant: PharmDr. Pavel Ondrejček, Ph.D. Student: Mgr. Vojtěch Grande Title of thesis: Development of a new model for the evaluation of compression phase of compaction process By evaluating the compression process during the preparation of tablets, we can find out information about the pressed material. This information is useful for the materials and tableting mixtures comparison, but also for predicting of potential problems during manufacturing. The theoretical part of this thesis is focused on the description of the methods most commonly used for the evaluation of pharmaceutical substances. Furthermore, there is a derivation of a new mathematical model for the evaluation of the compression phase of the compaction process and the corresponding script for the mathematical-statistical program QCExpert. In the experimental part of the thesis, this new proposed model is used for the evaluation of two known and frequently used fillers. Lactose and microcrystalline cellulose are used as model fillers. These are compressed separately and in a mixture. The results of this evaluation are compared with the force-displacement record and the stress relaxation. The results of the work showed that the new...
|
|
|
Evaluation of compressibility of granular powders and tableting mixtures with the high content of active substance.
Paris, Tereza ; Svačinová, Petra (advisor) ; Šklubalová, Zdeňka (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department od: Pharmaceutical Technology Consultant: PharmDr. Petra Svačinová, Ph.D. Student: Tereza Paris Title of Thesis: Evaluation of compressibility of granular powders and tableting mixtures with the high content of active substance This thesis deals with the evaluation of compressibility of granular powder and tableting mixtures with high drug content. Eleven batches of tablet formulations with different type of filler - microcrystalline cellulose or lactose and different type of extragranular disintegrants - sodium croscarmellose or crospovidone in concentrations of 2 %, 3,7 % or 5,4 % and two granular powders with only different type of filler were prepared by two methods. The first method was used to prepare tablets with the same height and the second method to prepare tablets with the same porosity as the oval tablets made from identical tableting mixtures. The compressibility was evaluated using the force-displacement method parameters and volumetric elastic recovery. Another tested parameter was tensile strength and, for one group of tablets, also porosity. The obtained results show that both, the type of filler and the type of extragranular disintegrant, had an effect on the force-displacement method parameters especially at...
|
|
|
Polymeric nanoparticles: platform for poorly water soluble drugs delivery
Roztočilová, Adéla ; Holas, Ondřej (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Mentor: PharmDr. Ondřej Holas, Ph.D. Student: Adéla Roztočilová Title of thesis: Polymeric nanoparticles as a platform for delivery of poorly water-soluble drugs Polymer nanoparticles can be used as drug carriers due to their beneficial properties. One of the advantages of polymeric nanoparticles is, for example, to increase the solubility of drugs in water. They have great potential in the therapy of inflammatory diseases such as Crohn's disease or in shifting cancer pharmacotherapy. The main objective of this thesis was to prepare polymeric nanoparticles with encapsulated curcumin as model active ingredient. Four types of poly(lactic-co-glycolic acid) (PLGA) copolymer were used to prepare the nanoparticles. Nanoprecipitation and emulsion evaporation methods were employed. The parameters evaluated were encapsulation efficiency, drug loading, particle size and polydispersity. Both the water phase, where two different surfactants were employed, and the organic phase were varied during the experiment. The experimental part also used a dissociation method where two types of PLGA copolymer were compared and during the dissociation, samples were taken at predetermined times to determine the total...
|
|
|
The influence of micronized poloxamer on the flow and compaction of a model tableting mixture
Dunlap, Brooke Alexandra ; Šklubalová, Zdeňka (advisor) ; Svačinová, Petra (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical Technology Supervisor: Assoc. Prof. Zdenka Šklubalová, Ph.D. Consultant: Sebastien Bailey Student: Brooke Alexandra Dunlap Title of Thesis: The influence of micronized poloxamer on the flow and compaction of a model tableting mixture Lubricants are an important excipient used in the production of tablets, they facilitate powder flow during manipulation, prevent powder sticking to the press during compression, and aid in tablet ejection. In this thesis the effect of four different concentrations 0.5, 1.0, 1.5, and 2.0 % w/w of micronized Poloxamer 188 on a model tableting mixture consisting of a 1:1 ratio of Microcrystalline Cellulose (MCC) and Lactose (L) was tested to determine its effectiveness as a lubricant for tablet manufacturing. Flow through an orifice, angle of repose, Hausner ratio, compressibility index, dynamics of consolidation, and powder bed porosity were tested. There was no increase in flowability of the powder at any concentration of P188 in any test used, all mixtures showed poor or very poor flow behaviour. Compression process was evaluated according to the force displacement method at three different compression forces (5 kN, 7 kN, 10 kN) and special attention was paid to ejection force. P188 is an...
|
|
|
The influence of micronized poloxamer on the flow and compaction of a model tableting mixture
Dunlap, Brooke Alexandra ; Šklubalová, Zdeňka (advisor) ; Svačinová, Petra (referee)
Charles University, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical Technology Supervisor: Assoc. Prof. Zdenka Šklubalová, Ph.D. Consultant: Sebastien Bailey Student: Brooke Alexandra Dunlap Title of Thesis: The influence of micronized poloxamer on the flow and compaction of a model tableting mixture Lubricants are an important excipient used in the production of tablets, they facilitate powder flow during manipulation, prevent powder sticking to the press during compression, and aid in tablet ejection. In this thesis the effect of four different concentrations 0.5, 1.0, 1.5, and 2.0 % w/w of micronized Poloxamer 188 on a model tableting mixture consisting of a 1:1 ratio of Microcrystalline Cellulose (MCC) and Lactose (L) was tested to determine its effectiveness as a lubricant for tablet manufacturing. Flow through an orifice, angle of repose, Hausner ratio, compressibility index, dynamics of consolidation, and powder bed porosity were tested. There was no increase in flowability of the powder at any concentration of P188 in any test used, all mixtures showed poor or very poor flow behaviour. Compression process was evaluated according to the force displacement method at three different compression forces (5 kN, 7 kN, 10 kN) and special attention was paid to ejection force. P188 is an...
|
|
|
Characterization of material for gelatin-based ultrasound brain phantom
Sasková, Marcela ; Smékalová, Monika (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Supervisor: Mgr. Monika Smékalová, Ph.D. Consultant: MUDr. Michael Bartoš Student: Marcela Sasková Title of thesis: Characterization of material for gelatin-based ultrasound brain phantom This thesis deals with the characterization of the material for a gelatin-based ultrasound phantom, which will subsequently serve as a teaching aid for medical students to localize brain tumors and practice ultrasound imaging. In the experimental part, samples of gelatin gels cross-linked with glutaraldehyde at different concentrations of scattering particles and glycerol were prepared to measure the acoustic parameters (speed of sound and attenuation coefficient) and the gray scale of the imaging and to perform thermal analysis. Gelatin is an inexpensive, readily available, non-toxic material that is highly soluble in hot water, making it a suitable starting material for phantom preparation. SiC and Al2O3 particles (0,3 µm and 3 µm) can be used to increase the echogenicity of the gelatin-based gel. Thanks to the scattering particles, it was possible to vary the gray level of the image and the attenuation coefficient depending on their amount. The best results were achieved with SiC alone, where the gray...
|
|
|
Study of disintegration time of capsules containing liquisolid systems
Bartůňková, Denisa ; Vraníková, Barbora (advisor) ; Svačinová, Petra (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Supervisor: doc. PharmDr. Barbora Vraníková, Ph.D. Consultant: MSc. Andreas Niederquell Candidate: Denisa Bartůňková Title of Diploma Thesis: Study of disintegration time of capsules containing liquisolid systems Liquisolid (LS) systems are free-flowing powder formed by dispersing a drug that is sorbed into a carrier. The resulting powder may be subsequently processed into the final dosage form (tablet, hard gelatine capsules and pellets). However, there is a risk of interactions between the solvent used and the capsule shell, which could affect its rate of disintegration. Therefore, this study is focused on the preparation of liquisolid capsules (LSC) and the evaluation of their disintegration rate in various media. Tested LSC contained pure solvents (polyethylene glycol 200 - PEG 200, polyethylene glycol 400 - PEG 400 or Transcutol ® HP - T-HP) or dispersion of cyclosporine A (cysA) in the above-mentioned solvents sorbed into a carrier material Neusilin® US2 (NUS2). The evaluation of LSS showed that LSC have a longer disintegration time compared to capsules containing only NUS2. However, LSC with both types of PEGs disintegrated more slowly than those with T-HP. Moreover, different...
|
|
|
Spray drying of drug suspension in lactose solution
Vlková, Klára ; Svačinová, Petra (advisor) ; Kováčik, Andrej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of: Pharmaceutical Technology Consultant: PharmDr. Petra Svačinová, Ph.D. Student: Klára Vlková Title of Thesis: Spray drying of a drug suspension in lactose solution Spray drying can be used to increase the solubility and thus bioavailability of drugs that are poorly soluble in water. In the present work, particles from a suspension of meloxicam in lactose solution were prepared by spray drying. The effect of the nozzle size of 0.7 mm and 1.4 mm, the effect of drug concentration of 0.5 g/100 ml and 1 g/100 ml, and the effect of lactose concentration on the properties of the resulting particles were investigated. The lactose solutions used had concentrations of 15, 20 and 25 %. The appearance and size of the formed particles were evaluated using optical and scanning electron microscopy (SEM). The amount of drug released was investigated using dissolution and the thermal characteristics of the particles were evaluated using differential scanning calorimetry (DSC). The evaluation by SEM and DSC was then performed again 6 months after the first measurement. The resulting particles were spherical in shape with no surface irregularities. Some of them contained clusters of meloxicam particles. At the second observation after 6 months,...
|
guest ::
RSS feed.