Most of drugs are only slightly soluble in the circulatory system of the human body. This reduces the efficiency of their use and that is why new ways how to increase their solubility are investigated. One way to improve the solubility of the drug is to reduce its particle size. Conventional techniques such as crushing or grinding usually do not guarantee a narrow particle size distribution, which is required for pharmaceuticals. Application of supercritical fluids, especially of supercritical CO₂, seems to be convenient method for the preparation of pharmaceuticals submicron particles or nanoparticles. The method enables the preparation of particles in a narrow size distribution and at the same time it does not leave any unwanted residues of solvents or other chemicals. The aim of this work is the micronization of ibuprofen particles using the supercritical fluid and characterization of formed products. The micronization of the particles was done using commercially available device Spe-ed SFE-4 in rapid expansion of supercritical solution mode. The applied temperatures and pressures were 308.15 K and 313.15 K and 200, 250 and 300 bar. The prepared particles were characterized using methods of X-ray diffraction, infrared spectroscopy, particle size distribution, scanning electron microscopy and tests of dissolution and permeability. Mean particles size was reduced from 180 μm (original ibuprofen) to 2.8-7.3 μm of the processed samples. The dissolution test confirmed better solubility and the permeability of newly formed particles improved.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Chronic venous insufficiency is a highly prevalent disease in the western population. Unfortunately, there is no causal treatment yet. A key role in the recommended therapeutic approaches, especially in the early stages, is the compression therapy accompanied by pharmacotherapy. This includes, inter alia, micronized diosmin. The following text summarizes the basic knowledge of its properties that determine its clinical use.

• Klíčová slova
• chronic venous insufficiency, diosmin, flavonoids, micronization,
• MeSH
• diosmin * terapeutické užití   MeSH
• flavonoidy MeSH
• lidé MeSH
• prevalence MeSH
• žilní insuficience * farmakoterapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• diosmin * MeSH
• flavonoidy MeSH

LDL-cholesterol subfractions have a different atherogenity; the most atherogenic are small LDL3 called small dense LDL. A clear relationship was proved between their concentration and early manifestation of ischaemic heart disease. In some instances they were found to act as an independent risk factor of cardiovascular disease. Their concentration depends to a great extent on the triacyglycerol concentration. They are found most frequently in patients with combined hyperlipidaemia, in associated metabolic syndrome and in patients with type 2 diabetes mellitus. Their plasma concentration can be reduced by non-pharmacological methods (restriction of animal fats, reduction of body weight, physical activity) as well as by pharmacological means (in particular fibrates). Micronized phenofibrate reduces significantly the concentration of small LDL3 and thus contributes to normalization of dyslipoproteinaemia and reduction of the risk of cardiovascular complications.

• MeSH
• fenofibrát terapeutické užití   MeSH
• hyperlipidemie krev   farmakoterapie   MeSH
• hypolipidemika terapeutické užití   MeSH
• kardiovaskulární nemoci krev   MeSH
• LDL-cholesterol krev   MeSH
• lidé MeSH
• rizikové faktory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• fenofibrát MeSH
• hypolipidemika MeSH
• LDL-cholesterol MeSH

Micronized phenofibrate 200 mg was administered in clinical trial to 30 patients with dyslipidaemia. Their average age was 51.9 years (10 with type 2a, 12 with type 2b and 8 with types 4 and 5). After 12 weeks of treatment significant improvement of the whole lipid profile was achieved. The total cholesterol declined in different sub-groups by 16, 17 and 20% resp. LDL cholesterol declined by 20 and 18 per cent in types 2a and 2b, in types 4 and 5 it was not assessed (it was not possible to use Friedewald's equation). Triglycerides declined by 39, 45 and 75%. The HDL concentration increased by 16, 27 and 25%. The atherogenic indexes TCh/HDL-Ch declined by 28, 36 and 32%. LDL-Ch/HDL-Ch dropped by 30 and 34%. The extent of the hypolipidaemic effect depended on the baseline value: the more pathological the baseline value, the more marked the improvement. As to other investigated indicators there was a significant rise of the apolipoprotein AI and Lp AI particle concentration. Apoprotein B declined insignificantly. Uric acid declined significantly by 28%. Fibrinogen dropped significantly only in type 2a. The lipoprotein(a) concentration did not change significantly. The drug was very well tolerated and undesirable effects were minimal. Micronized phenofibrate (Lipanthyl 200 M) due to its comprehensive favourable effect on the entire lipid profile and other risk factors can prove useful in the treatment of all types of dyslipidaemias (with the exception of type I). As compared with Lipanthyl 100, the better pharmacokinetic properties make it possible to reduce the dose from 300 mg/day and it can be administered in a single daily dose.

• MeSH
• fenofibrát aplikace a dávkování   MeSH
• hyperlipidemie krev   farmakoterapie   MeSH
• hypolipidemika aplikace a dávkování   MeSH
• lékové formy MeSH
• lidé středního věku MeSH
• lidé MeSH
• velikost částic MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• klinické zkoušky MeSH
• Názvy látek
• fenofibrát MeSH
• hypolipidemika MeSH
• lékové formy MeSH

BACKGROUND: The aim of the study was to approve the hypolipidemic potency of the new drug from the group of fibrate derivates Lipanthyl 200 M(R) (micronized fenofibrate, cps a 200 mg, Laboratoires Fournier, France) in patients with familial hyperlipoproteinemias. The drug has been administered in constant dose of 200 mg daily with the evening meal for three months. Clinical examinations and monitoring of safety laboratory have been performed in addition to complete analysis of lipids, lipoproteins and apolipoproteins during the study. METHODS AND RESULTS: The group of 30 patients consisted from 14 heterozygotes of familial hypercholesterolemia and 16 patients affected by familial combined hyperlipidemia. Levels of total, HDL- and LDL-cholesterol, triglycerides, apolipoproteins A-I and B and Lp(a) have been measured and concentrations of fibrinogen in plasma as well. Concentration of total cholesterol 8.29 +/- 1.3 mmol/l on the beginning of the study decreased after one and three months of the treatment to 6.94 +/- 1.19 resp. 6.98 +/- 1.21 mmol/l, concentration of triglycerides has been reduced from 2.86 +/- 1.29 mmol/l to 1.70 +/- 0.86 and 1.74 +/- 0.99 mmol/l respectively HDL-cholesterol raised from 1.14 +/- 0.32 mmol/l to 1.27 +/- 0.36 and to 1.34 +/- 0.37 mmol/l in contrast to decrease of LDL-cholesterol 5.88 +/- 1.53 mmol/l on the beginning of the study to 4.87 +/- 1.49 and 4.79 +/- 1.60. Apo B in plasma fall after three month period of the treatment from 1.83 +/- 0.43 g/l to 1.46 +/- 0.47 g/l. On the other hand the concentration of apolipoprotein apo A-I1.20 +/- 0.35 g/l increased to 1.40 +/- 0.32 g/l. Fibrinogen in plasma was reduced from 3.63 +/- 0.69 g/l to 2.77 +/- 0.50 g/l. Also this decrease was statistically significant. CONCLUSIONS: Micronized fenofibrate is a potent hypolipidemic drug with only rare side effects. It is very good tolerated by the patients. Micronized fenofibrate is particularly prescribed for combined hyperlipidemia, however we can use it also in some patients with familial hypercholesterolemia. For to the treatment very resistant hyperlipoproteinemias we should consider combined drug therapy.

• MeSH
• dospělí MeSH
• familiární kombinovaná hyperlipidemie krev   farmakoterapie   genetika   MeSH
• fenofibrát aplikace a dávkování   MeSH
• fibrinogen analýza   MeSH
• heterozygot MeSH
• hyperlipoproteinemie typ II krev   farmakoterapie   genetika   MeSH
• hypolipidemika aplikace a dávkování   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lipidy krev   MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• fenofibrát MeSH
• fibrinogen MeSH
• hypolipidemika MeSH
• lipidy MeSH

This study is focused on in vitro permeation of the original Czech compound, a skin/mucosa tissue regeneration promoter, known under the international nonproprietary name "alaptide," in micronized and nanonized forms. Alaptide showed a great potential for local applications for treatment and/or regeneration of the injured skin. The above mentioned technological modifications influence the permeation of alaptide through artificial or biological membranes, such as PAMPA or skin. The permeation of micronized and nanonized form of alaptide formulated to various semisolid pharmaceutical compositions through full-thickness pig ear skin using a Franz cell has been investigated in detail. In general, it can be concluded that the nanonized alaptide permeated through the skin less than the micronized form; different observations were made for permeation through the PAMPA system, where the micronized form showed lower permeation than the nanonized alaptide.

• MeSH
• cyklické peptidy * chemie   farmakologie   MeSH
• kůže * MeSH
• membrány umělé * MeSH
• nanočástice chemie   MeSH
• neuropeptidy * chemie   farmakologie   MeSH
• permeabilita MeSH
• prasata MeSH
• umělá kůže * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cyclo(alanine-(1-amino-1-cyclopentane)carbonyl) MeSH Prohlížeč
• cyklické peptidy * MeSH
• membrány umělé * MeSH
• neuropeptidy * MeSH

The study evaluates the micronized poloxamers Lptrol micro127 (poloxamer 407) and Lptrol micro 68 (poloxamer 188) as lubricants in combination with the dry binders microcrystalline cellulose and spray-dried lactose. Magnesium stearate was employed as the comparative lubricant. The parameters under study included energy for friction, plasticity, ejection force, tensile strength of tablets, and disintegration time of tablets. The factors of influence were the concentration of lubricants, compression force, and mixing parameters. The lubricating effect of micronized poloxamers was smaller than that of magnesium stearate. Higher concentrations of poloxamers decreased the tensile strength of tablets from microcrystalline cellulose, shortened the disintegration time, and slightly prolonged the disintegration time in the case of spray-dried lactose. Parameters of mixing of dry binders with poloxamers influenced the tested parameters of compression more in the case of spray-dried lactose. In microcrystalline cellulose, they influenced more the tensile strength and disintegration time of tablets.

• MeSH
• časové faktory MeSH
• celulosa chemie   MeSH
• farmaceutická chemie MeSH
• farmaceutická technologie metody   MeSH
• kyseliny stearové chemie   MeSH
• laktosa chemie   MeSH
• lubrikanty chemie   MeSH
• pevnost v tahu MeSH
• poloxamer chemie   MeSH
• pomocné látky chemie   MeSH
• rozpustnost MeSH
• tablety MeSH
• tření MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• celulosa MeSH
• kyseliny stearové MeSH
• laktosa MeSH
• lubrikanty MeSH
• microcrystalline cellulose MeSH Prohlížeč
• poloxamer MeSH
• pomocné látky MeSH
• stearic acid MeSH Prohlížeč
• tablety MeSH

Compression experiments on micron-scale specimens and acoustic emission (AE) measurements on bulk samples revealed that the dislocation motion resembles a stick-slip process - a series of unpredictable local strain bursts with a scale-free size distribution. Here we present a unique experimental set-up, which detects weak AE waves of dislocation slip during the compression of Zn micropillars. Profound correlation is observed between the energies of deformation events and the emitted AE signals that, as we conclude, are induced by the collective dissipative motion of dislocations. The AE data also reveal a two-level structure of plastic events, which otherwise appear as a single stress drop. Hence, our experiments and simulations unravel the missing relationship between the properties of acoustic signals and the corresponding local deformation events. We further show by statistical analyses that despite fundamental differences in deformation mechanism and involved length- and time-scales, dislocation avalanches and earthquakes are essentially alike.

• Publikační typ
• časopisecké články MeSH

Plastic deformation of micron-scale crystalline materials differs considerably from bulk samples as it is characterized by stochastic strain bursts. To obtain a detailed picture of the intermittent deformation phenomena, numerous micron-sized specimens must be fabricated and tested. An improved focused ion beam fabrication method is proposed to prepare non-tapered micropillars with excellent control over their shape. Moreover, the fabrication time is less compared with other methods. The in situ compression device developed in our laboratory allows high-accuracy sample positioning and force/displacement measurements with high data sampling rates. The collective avalanche-like motion of the dislocations is observed as stress decreases on the stress-strain curves. An acoustic emission (AE) technique was employed for the first time to study the deformation behavior of micropillars. The AE technique provides important additional in situ information about the underlying processes during plastic deformation and is especially sensitive to the collective avalanche-like motion of the dislocations observed as the stress decreases on the deformation curves.

• Klíčová slova
• in situ deformation, acoustic emission, micropillar compression, microsample fabrication,
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A new method for triggering the burst liberation of encapsulated sub-micron particles from carrier particles using embedded microorganisms has been developed. Triggering mechanisms such as those based on chemical, light, thermal, or magnetic stimuli are known, but man-made particles are not yet able to replicate the concept of "dormancy" found in biological systems in the form of spores or seeds that survive in an inactive state and start to grow only once favourable environmental conditions are encountered. An engineered particle system that mimics this property by embedding viable yeast cells into synthetically made alginate microcapsules is reported in the present work. Cell growth and division is used as a triggering mechanism for stimuli-responsive release of the encapsulated content. The hybrid living/artificial capsules were formed by an inkjet printing process and the mechanism of biologically triggered release was shown using fluorescently labelled liposomes.

• Publikační typ
• časopisecké články MeSH