The aim of this study was to investigate the molecular structures of tadalafil solid dispersions prepared by different techniques and further to relate them to surface free energy information indicating the final amorphousness of the product. Thus, we tried to complement the existing knowledge of solid dispersion formation. Poorly water-soluble tadalafil was combined with different polymers, i.e. Kollidon® 12 PF, Kollidon® VA 64 and Soluplus®, to form model systems. To assess the extent of drug-polymer miscibility, we studied model solid dispersion surface energy using inverse gas chromatography and phase micro-structure using confocal Raman microscopy. The selection of the preparation method was found to play a crucial role in the molecular arrangement of the incorporated drug and the polymer in resulting solid dispersion. Our results showed that a lower surface free energy indicated the formation of a more homogeneous solid dispersion. Conversely, a higher surface free energy corresponded to the heterogeneous systems containing tadalafil amorphous clusters that were captured by Raman mapping. Thus, we successfully introduced a novel evaluation approach of the drug molecular arrangement in solid dispersions that is especially useful for examining the miscibility of the components when the conventional characterizing techniques are inconclusive or yield variable results.
- MeSH
- chromatografie plynová MeSH
- polymery * chemie MeSH
- povidon * chemie MeSH
- rozpustnost MeSH
- tadalafil chemie MeSH
- Publikační typ
- časopisecké články MeSH
Poly(d,l-lactide)/polyethylene glycol (PLA/PEG) micro/nanofibers loaded with paclitaxel (PTX, 10 wt%) were prepared by needless electrospinning technology, which allows large scale production for real medicinal practice. The fiber structure and properties were investigated by several methods including scanning electron microscopy, nitrogen adsorption/desorption isotherm measurements, differential scanning calorimetry, and X-ray diffraction measurements to examine their morphology (fiber diameter distribution, specific surface area, and total pore volume), composition, drug-loading efficiency, and physical state. An HPLC-UV method was optimized and validated to quantify in vitro PTX release into PBS. The results showed that the addition of PEG into PLA fibers promoted the release of higher amounts of hydrophobic PTX over prolonged time periods compared to fibers without PEG. An in vitro cell assay demonstrated the biocompatibility of PLA/PEG fibrous materials and showed significant cytotoxicity of PTX-loaded PLA/PEG fibers against a human fibrosarcoma HT1080 cell line. The chick chorioallantoic membrane assay proved that PTX-loaded fibers exhibited antiangiogenic activity, with a pronounced effect in the case of the PEG-containing fibers. In vivo evaluation of PTX-loaded PLA/PEG fibers in a human fibrosarcoma recurrence model showed statistically significant inhibition in tumor incidence and growth after primary tumor resection compared to other treatment groups.
- MeSH
- buněčná smrt účinky léků MeSH
- difrakce rentgenového záření MeSH
- inhibitory angiogeneze farmakologie MeSH
- kur domácí MeSH
- lidé MeSH
- lokální recidiva nádoru patologie prevence a kontrola MeSH
- myši nahé MeSH
- nádorové buněčné linie MeSH
- nanovlákna chemie ultrastruktura MeSH
- nosiče léků chemie MeSH
- paclitaxel farmakologie MeSH
- polyestery chemie MeSH
- polyethylenglykoly chemie MeSH
- tělesná hmotnost MeSH
- teplota MeSH
- tumor burden účinky léků MeSH
- uvolňování léčiv * MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Biochar application is a widely investigated topic nowadays, and precisely described biochar parameters are key information for the understanding of its behaviour in soil and other media. Pore structure and surface properties determine biochar fate. However, there is lack of complex, investigative studies describing the influence of biomass properties and pyrolysis conditions on the pore structure of biochars. The aim of our study was to evaluate a wide range of gathered agriculture residues and elevated pyrolysis temperature on the biochar surface properties and pore composition, predicting biochar behaviour in the soil. The biomass of herbaceous and wood plants was treated by slow pyrolysis, with the final temperature ranging from 400 to 600 °C. Specific surface ranged from 124 to 511 cm2 g-1 at wood biochar and from 3.19 to 192 cm2 g-1 at herbaceous biochar. The main properties influencing biochar pore composition were increasing pyrolysis temperatures and lignin (logarithmically) and ash contents (linearly) of biomass. Increasing lignin contents and pyrolysis temperatures caused the highest biochar micropore volume. The total biochar pore volume was higher of wood biomass (0.08-0.3 cm-3 g-1). Biochars of wood origin were characterised by skeletal density ranging from 1.479 to 2.015 cm3 g-1 and herbaceous ones 1.506-1.943 cm3 g-1, and the envelope density reached 0.982 cm3 g-1 at biochar of wheat grain origin and was generally higher at biochars of herbaceous origin. Density was not pyrolysis temperature dependent.
BACKGROUND: Essential oil components (EOCs) are known for their antifungal properties; however, their high volatility limits their application as antimicrobial agents. Strategies used for controlling the volatility of EOCs include encapsulation or loading into porous materials. This study evaluated the in vitro antifungal activity of selected EOCs (carvacrol, cinnamaldehyde, eugenol and thymol) against the fungus Aspergillus niger when loaded into MCM-41 and β-cyclodextrin (β-CD). RESULTS: Carvacrol and thymol in Mobil Composition of Matter No. 41 (MCM-41) displayed remarkable enhanced antifungal properties in comparison to the pure or β-CD-encapsulated EOCs. In fact, carvacrol and thymol were able to maintain antifungal activity and inhibit fungal growth for 30 days, suggesting better applicability of these EOCs as natural preservatives. CONCLUSIONS: The sustained antifungal effect of EOCs encapsulated into silica mesoporous supports was described.
- MeSH
- antifungální látky chemie farmakologie MeSH
- Aspergillus niger účinky léků růst a vývoj MeSH
- beta-cyklodextriny MeSH
- cinnamáty chemie farmakologie MeSH
- konzervace potravin metody MeSH
- lidé MeSH
- monoterpeny chemie farmakologie MeSH
- oleje prchavé chemie farmakologie MeSH
- oleje rostlin chemie farmakologie MeSH
- oxid křemičitý MeSH
- potravinářská mikrobiologie MeSH
- potravinářské konzervační látky chemie farmakologie MeSH
- rostlinné extrakty chemie farmakologie MeSH
- volatilizace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
