Nowadays, most of the newly developed active pharmaceutical ingredients (APIs) consist of cohesive particles with a mean particle size of <100μm, a wide particle size distribution (PSD) and a tendency to agglomerate, therefore they are difficult to handle in continuous manufacturing (CM) lines. The current paper focuses on the impact of various glidants on the bulk properties of difficult-to-handle APIs. Three challenging powders were included: two extremely cohesive APIs (acetaminophen micronized (APAPμ) and metoprolol tartrate (MPT)) which previously have shown processing issues during different stages of the continuous direct compression (CDC)-line and a spray dried placebo (SD) powder containing hydroxypropylmethyl cellulose (HPMC), known for its sub-optimal flow with a high specific surface area (SSA) and low density. Four flow-enhancing excipients were used: a hydrophilic (Aerosil® 200) and hydrophobic (Aerosil® R972) fumed silica grade, a mesoporous silica grade (Syloid® 244FP), and a calcium phosphate excipient (TRI-CAFOS® 200-7). The APIs and binary API/glidant blends (varied between 0.5-2.75 w/w%) were characterized for their bulk properties relevant for CDC. The results indicated that optimizing different bulk parameters (e.g., density, flow, compressibility..) of an API required varying weight percentages of the glidant (e.g., different surface area coverage (SAC)) depending on the APIs. Moreover, even at similar SAC, the impact of the glidant on the bulk characteristic of the APIs depended on the glidant type properties. While nano-sized silicon dioxide were effective for improving the flowability of a powder, other glidants (mesoporous silica and tricalcium phosphate (TCP)) showed also promise as alternatives. Additionally, an excess of glidant, referred to as oversilication, negatively impacted some bulk parameters, but other characteristics were unaffected. Finally, to determine the appropriate concentration of the different classes of glidants, SAC calculations, an understanding of the glidant's working mechanism, and knowledge about the API's characteristics (i.e., morphology, compressibility, flowability, aeration, density, and wall friction) are required. This study confirmed the necessity of including various material characterization techniques to assess the impact of glidants on the bulk characteristics of APIs.
- MeSH
- deriváty hypromelózy * chemie MeSH
- farmaceutická chemie metody MeSH
- fosforečnany vápenaté * chemie MeSH
- hydrofobní a hydrofilní interakce MeSH
- metoprolol * chemie MeSH
- nerozplněné léky MeSH
- oxid křemičitý chemie MeSH
- paracetamol * chemie MeSH
- pomocné látky * chemie MeSH
- prášky, zásypy, pudry * MeSH
- příprava léků metody MeSH
- reologie * MeSH
- velikost částic * MeSH
- Publikační typ
- časopisecké články MeSH
Autoři v článku prezentují epidemiologii, rizikové faktory přispívající ke vzniku urolitiáz, věnují se dále laboratornímu vyšetření u litiatiků, včetně problematiky analýzy složení konkrementů a jeho významu. Hlavním cílem článku je předložení metod neinvazivní léčby jednotlivých typů litiázy, především metafylaxe u pacientů s litiázou, a to jak režimových opatřeních, tak i užití farmak, které přispívají ke snížení četností recidiv litiázy, ale i komplikacím, které jsou s tímto onemocněním spojené.
The authors present the epidemiology, risk factors contributing to the development of urolithiasis, laboratory examination in lithiatic patients, including the analysis of the composition of concrements and its significance. The main goal of the article is to present the methods of non-invasive treatment of different types of lithiasis, especially metaphylaxis in patients with lithiasis, both regimen measures and the use of drugs that contribute to reducing the frequency of recurrences of lithiasis, as well as complications associated with this disease
- MeSH
- alopurinol farmakologie terapeutické užití MeSH
- analýza moči metody MeSH
- cystinurie farmakoterapie komplikace MeSH
- difrakce rentgenového záření metody MeSH
- diuretika farmakologie terapeutické užití MeSH
- hydroxyapatit terapeutické užití MeSH
- hyperkalciurie farmakoterapie komplikace MeSH
- hyperoxalurie farmakoterapie komplikace MeSH
- hyperurikemie farmakoterapie komplikace MeSH
- infekce močového ústrojí etiologie komplikace MeSH
- kaliumcitrát farmakologie terapeutické užití MeSH
- kaménky etiologie klasifikace terapie MeSH
- klinické laboratorní techniky metody MeSH
- lidé MeSH
- oxaláty škodlivé účinky MeSH
- rizikové faktory MeSH
- urolitiáza * diagnóza farmakoterapie prevence a kontrola MeSH
- vápník dietní terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
220 stran : ilustrace (některé barevné) ; 24 cm
Publikácia, ktorá sa zameriava na biokompatibilné kostné cementy vyrobené z fosforečnanu vápenatého a používané v liečbe defektov kostí a chrupavky. Určené odbornej verejnosti.
- MeSH
- biokompatibilní materiály MeSH
- fosforečnany vápenaté MeSH
- kostní cementy MeSH
- nemoci chrupavky MeSH
- nemoci kostí MeSH
- regenerace kostí MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- biomedicínské inženýrství
- technika lékařská, zdravotnický materiál a protetika
- ortopedie
- NLK Publikační typ
- kolektivní monografie
PURPOSE OF THE STUDY: The preclinical study aimed to compare the healing of segmental bone defects treated with biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel with the established autologous spongioplasty. Another aim was to evaluate the hydrogel as a scaffold for osteoinductive growth factor of bone morphogenetic protein-2 (BMP-2) and stem cells. MATERIAL AND METHODS: The study was conducted in an in vivo animal model. A standardized rabbit model of a 15 mm long segmental bone defect of left radius was used. A total of 40 animals were divided into 5 groups of 8 individuals. In the KO- (negative control) group, the created defect was left to heal spontaneously. In the KO+ (positive control) group, the defect was filled with morselized bone autograft prepared from the resected segment. In the study group A, the defect was filled with hydrogel based on hyaluronic acid derivative and tricalcium phosphate. In the study group B, the defect was filled with hydrogel based on hyaluronic acid derivative, tricalcium phosphate and bone marrow aspirate. In the study group C, the defect was filled with hydrogel based on hyaluronic acid derivative, tricalcium phosphate, bone marrow aspirate and BMP-2. Healing was assessed using radiographs at 1, 6, and 12 weeks postoperatively and histology specimens were collected at 16 weeks postoperatively. RESULTS: Altogether 35 rabbits survived (KO- 7, KO+ 7, A 7, B 6, C 8) until the end of the study. As concerns the radiographic assessment, the best results were achieved by the groups KO+ and C, where new bone formation across the entire width of the bone defect was clearly seen at 6 and 12 weeks and the osteotomy line was completely healed too. At 12 weeks, complete bone remodelling was observed in all animals in the group KO+, whereas in the group C, bone remodelling was fully completed in 5 animals and partially completed in 3 animals. In terms of histological assessment, however, the best results were achieved by the group C, where the bone defect was completely remodelled into lamellar bone in 7 specimens, while in 1 specimen it healed with bony callus formation. In the group KO+, the defect was healed in 4 specimens by cartilaginous callus with loci of remodelling into bony callus, in 2 specimens the bony callus was predominant with cartilaginous callus areas, and only one defect was completely remodelled into lamellar bone. DISCUSSION: Compared to autografts that manifest osteogenic, osteoinductive and osteoconductive properties, the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel has osteoconductive properties only. Thus, it was also tested in our study as a scaffold for bone marrow cells and BMP-2 osteoinductive growth factor. Thanks to its semi-liquid properties, the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel is a promising material for use in 3D printing. CONCLUSIONS: The preclinical study in an in vivo animal model confirmed the beneficial effect of the biodegradable hyaluronic acid and tricalcium phosphate-based hydrogel on the healing of critical-size segmental bone defects. Better healing of these defects was also confirmed for filling composed of hydrogel and BMP-2 osteoinductive growth factor. The benefit of bone marrow aspirate mixed with hydrogel was not confirmed. KEY WORDS: bone defect, non-union, rabbit, hyaluronic acid, calcium phosphate, stem cells, BMP-2, scaffold, bone healing, spongioplasty.
- MeSH
- fosforečnany vápenaté * farmakologie MeSH
- hydrogely farmakologie MeSH
- kostní morfogenetický protein 2 * MeSH
- králíci MeSH
- kyselina hyaluronová * farmakologie MeSH
- modely nemocí na zvířatech MeSH
- radius chirurgie zranění MeSH
- regenerace kostí účinky léků MeSH
- tkáňové podpůrné struktury * MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
We explored the potential of a fungal strain Aspergillus costaricensis KS1 for modulating growth and nutrient mobilization in rice. At laboratory conditions, there was a decline in pH of the medium on inoculation with the strain and the production of citric acid was observed under broth conditions. Similarly, there was higher solubilization of tricalcium phosphate and siderophore production in liquid medium on inoculation with the strain. The effect of inoculation of KS1 was studied in rice and higher growth and yield were observed on inoculation compared to control. The content of phosphorus and iron in stem and roots of KS1 inoculated plants was higher in comparison with uninoculated control. There was also increased availability of phosphorus and iron content in soil grown with KS1 inoculated plants. In addition, inoculation with strain resulted in a higher content of volatile organic compounds such as linoleic acid, linolenic acid, and ethyl isoallocholate in stem of rice. A. costaricensis KS1 can be used for improving phosphorus and iron nutrition and impart tolerance against stresses in rice.
- MeSH
- Aspergillus * metabolismus růst a vývoj MeSH
- fosfor * metabolismus analýza MeSH
- fosforečnany vápenaté metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- kořeny rostlin mikrobiologie metabolismus MeSH
- kyselina citronová metabolismus MeSH
- půdní mikrobiologie MeSH
- rýže (rod) * mikrobiologie metabolismus růst a vývoj MeSH
- siderofory * metabolismus MeSH
- stonky rostlin mikrobiologie metabolismus chemie MeSH
- těkavé organické sloučeniny * metabolismus analýza MeSH
- železo * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
The use of knowledge from technetium radiochemistry (even from nuclear medicine applications) allows us to select an sorbent for 99mTc radionuclide sorption, which is hydroxyapatite. Using radioisotope indication, the 99mTcO4- sorption process on synthetic hydroxyapatite was studied by the batch method in the presence of SnCl2 and FeSO4 reducing agents. The complexing organic ligands' effect on the 99mTcO4- sorption under reducing conditions was investigated. In the presence of Sn2+ ions without the addition of organic ligand, the sorption percentage reached above 90% independently of the environment. In the presence of Fe2+ ions without the addition of organic ligand, the sorption of 99mTcO4- was significantly lower and was at approximately 6%, depending on the concentration of Fe2+ ions in solution. The effect of complexing organic ligands on the 99mTcO4- sorption on hydroxyapatite from the aqueous solution, acetate buffer and phosphate buffer decreases in the following order for Sn2+: oxalic acid > ethylenediaminetetraacetic acid > ascorbic acid. In the presence of Fe2+ ions without organic ligands, the sorption reached up to 15% depending on the composition of the solution. The addition of oxalic acid and ascorbic acid increased the sorption up to 80%. The ethylenediaminetetraacetic acid had no significant effect on the sorption of technetium on hydroxyapatite.
PURPOSE: Osteoporosis is a severe health problem with social and economic impacts on society. The standard treatment consists of the systemic administration of drugs such as bisphosphonates, with alendronate (ALN) being one of the most common. Nevertheless, complications of systemic administration occur with this drug. Therefore, it is necessary to develop new strategies, such as local administration. METHODS: In this study, emulsion/dispersion scaffolds based on W/O emulsion of PCL and PF68 with ALN, containing hydroxyapatite (HA) nanoparticles as the dispersion phase were prepared using electrospinning. Scaffolds with different release kinetics were tested in vitro on the co-cultures of osteoblasts and osteoclast-like cells, isolated from adult osteoporotic and control rats. Cell viability, proliferation, ALP, TRAP and CA II activity were examined. A scaffold with a gradual release of ALN was tested in vivo in the bone defects of osteoporotic and control rats. RESULTS: The release kinetics were dependent on the scaffold composition and the used system of the poloxamers. The ALN was released from the scaffolds for more than 22 days. The behavior of cells cultured in vitro on scaffolds with different release kinetics was comparable. The difference was evident between cell co-cultures isolated from osteoporotic and control animals. The PCL/HA scaffold show slow degradation in vivo and residual scaffold limited new bone formation inside the defects. Nevertheless, the released ALN supported bone formation in the areas surrounding the residual scaffold. Interestingly, a positive effect of systemic administration of ALN was not proved. CONCLUSION: The prepared scaffolds enabled tunable control release of ALN. The effect of ALN was proved in vitro and in in vivo study supported peri-implant bone formation.
- MeSH
- alendronát * farmakologie MeSH
- emulze farmakologie MeSH
- hydroxyapatit farmakologie MeSH
- inhibitory kostní resorpce * farmakologie MeSH
- krysa rodu rattus MeSH
- osteoblasty MeSH
- osteogeneze MeSH
- osteoklasty MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
This research work is focused on the investigation of newly developed titania sol-gel coatings containing silver, calcium and phosphate with appropriate abilities to be implanted into the human body. These abilities include adhesion, bioactivity, antibacterial property and cytocompatibility of prepared coatings. Four types of coatings were applied on a titanium substrate by dip-coating technique under different conditions (TCP1, TCP2, TCPA1 and TCPA2). Surfaces of coatings after the firing without silver featured different distribution of circular areas containing Ca. The coatings TCPA1 and TCPA2 were made up of unhomogeneously situated silver. Adhesion of the coatings to the substrates was measured by a tape test. All types of the coatings demonstrated very good adhesion. Isolated cracks that appeared during the firing did not have a negative influence on the adhesion properties. Bioactivity of the coatings was tested in vitro using a simulated body fluid. Three of the four types demonstrated bioactive properties (TCP1, TCP2 and TCPA2), that is, precipitation of crystalline hydroxyapatite as was confirmed by X-ray diffraction. The antibacterial effect (against Escherichia coli and Staphylococcus epidermidis) and cytotoxicity (toward L929 and U-2 OS cell lines, direct and indirect test) were then tested. All the coatings demonstrated very good antibacterial effect against both bacteria after 4- and 24-hr interaction. All the coating types were evaluated as cytocompatible in the indirect test. Cells were able to grow even directly on the coatings.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- biokompatibilní potahované materiály chemie farmakologie MeSH
- Escherichia coli MeSH
- hydroxyapatit farmakologie MeSH
- lidé MeSH
- stříbro * farmakologie MeSH
- titan * chemie farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Collagen I-based foams were modified with calcined or noncalcined hydroxyapatite or calcium phosphates with various particle sizes and pores to monitor their effect on cell interactions. The resulting scaffolds thus differed in grain size, changing from nanoscale to microscopic, and possessed diverse morphological characteristics and resorbability. The materials' biological action was shown on human bone marrow MSCs. Scaffold morphology was identified by SEM. Using viability test, qPCR, and immunohistochemical staining, we evaluated the biological activity of all of the materials. This study revealed that the most suitable scaffold composition for osteogenesis induction is collagen I foam with calcined hydroxyapatite with a pore size of 360 ± 130 μm and mean particle size of 0.130 μm. The expression of osteogenic markers RunX2 and ColI mRNA was promoted, and a strong synthesis of extracellular protein osteocalcin was observed. ColI/calcined HAP scaffold showed significant osteogenic potential, and can be easily manipulated and tailored to the defect size, which gives it great potential for bone tissue engineering applications.
BACKGROUND: The last definition of the post-enucleation socket syndrome (PESS) by Tyers and Collin-formulated almost 40 years ago in 1982-is predominantly based on the clinical characteristics and does not include the insights of newer studies into the pathophysiological mechanism of the PESS. METHODS: A systematic PubMed literature review regarding the pathophysiological mechanism of the PESS was performed, and results were comprised to give an overview of the current knowledge of the PESS including the exact pathophysiological mechanism. RESULTS: The primarily postulated pathophysiological mechanism of the PESS was the atrophy of orbital tissues, especially of fat, resulting in variable clinical findings. Newer studies using high-resolution computed tomography and magnetic resonance imaging or performing histopathological analyses found no orbital fat atrophy but rather a rotatory displacement of the orbital tissues from superior to posterior and from posterior to inferior together with the retraction of the extraocular muscles and a possible volume loss of the orbital implant by resorption if it is manufactured from hydroxyapatite. PESS results in a backward tilt of the superior fornix, a deep superior sulcus, a pseudo-ptosis, a lower eyelid elongation and laxity, a shallower inferior fornix, as well as enophthalmos and may lead to an inability of wearing ocular prostheses. CONCLUSIONS: A novel and comprehensive definition of the PESS is proposed: PESS is a multifactorial and variable syndrome caused by a rotatory displacement of orbital contents together with the retraction of the extraocular muscles and possible resorption of the orbital implant if it is manufactured from hydroxyapatite.
- MeSH
- atrofie MeSH
- enukleace oka MeSH
- hydroxyapatity MeSH
- lidé MeSH
- nemoci orbity * diagnóza etiologie chirurgie MeSH
- oční protézy škodlivé účinky MeSH
- orbitální implantáty * škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH