Despite the increasing interest in pharmaceutical use of mesoporous silica, there is still only limited knowledge on mechanisms of pore loading and subsequent drug desorption and release. Hence the aim of this work was to address the mechanistic aspects of drug loading into the mesoporous silica pores and to minimise the risk of pore clogging. Hydrophilic solvents (polysorbate 20 and polyethylene glycol 200) with high dissolving capacity for the model drug celecoxib were studied for their surface tension as well as dynamic viscosity by considering hydration. As an innovation in liquisolid systems preparation, a rather simple drug loading method on a mesoporous carrier was introduced by using semi-volatile solvent mixtures. Fast liquid loading into the pores was achieved due to the lowered viscosity and surface tension of the whole solvent system. Drug release kinetics suggested that lipid-based formulations belonging to class IV of Lipid Formulation Classification System may exhibit a lower risk of incomplete desorption from a carrier. The utilisation of volatile solvents during preparation had no negative impact on the liquisolid systems' dissolution behaviour. All prepared formulations showed similar significantly faster dissolution profiles compared to the physical mixture. The novel approach has potential to promote liquisolid applications in pharmaceutics.
- MeSH
- chemie farmaceutická metody MeSH
- diferenciální skenovací kalorimetrie metody MeSH
- farmaceutická technologie metody MeSH
- hydrofobní a hydrofilní interakce MeSH
- kinetika MeSH
- léčivé přípravky chemie MeSH
- lipidy chemie MeSH
- nosiče léků chemie MeSH
- oxid křemičitý chemie MeSH
- polysorbáty chemie MeSH
- propylenglykol chemie MeSH
- rozpouštědla chemie MeSH
- rozpustnost účinky léků MeSH
- tablety chemie MeSH
- Publikační typ
- časopisecké články MeSH
Amplification of DNA templates from whole blood with Taq DNA polymerase remains a difficult task worldwide. Using a real-time PCR setup and a buffer supplemented with 1M 1,2-propanediol, 0.2M trehalose, and SYBR green I we show a reliable technique for genotyping in mice and detection of single-nucleotide polymorphisms/mutations in humans. Elimination of DNA extraction and use of the common Taq DNA polymerase and DNA dye bring about substantial savings in labor and cost.
- MeSH
- DNA chemie MeSH
- genotyp MeSH
- jednonukleotidový polymorfismus genetika MeSH
- kvantitativní polymerázová řetězová reakce metody MeSH
- lidé MeSH
- myši MeSH
- organické látky chemie MeSH
- propylenglykol chemie MeSH
- pufry MeSH
- Taq-polymerasa chemie MeSH
- trehalosa chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Quantitative real-time PCR (qPCR) is becoming increasingly important for DNA genotyping and gene expression analysis. For continuous monitoring of the production of PCR amplicons DNA-intercalating dyes are widely used. Recently, we have introduced a new qPCR mix which showed improved amplification of medium-size genomic DNA fragments in the presence of DNA dye SYBR green I (SGI). In this study we tested whether the new PCR mix is also suitable for other DNA dyes used for qPCR and whether it can be applied for amplification of DNA fragments which are difficult to amplify. RESULTS: We found that several DNA dyes (SGI, SYTO-9, SYTO-13, SYTO-82, EvaGreen, LCGreen or ResoLight) exhibited optimum qPCR performance in buffers of different salt composition. Fidelity assays demonstrated that the observed differences were not caused by changes in Taq DNA polymerase induced mutation frequencies in PCR mixes of different salt composition or containing different DNA dyes. In search for a PCR mix compatible with all the DNA dyes, and suitable for efficient amplification of difficult-to-amplify DNA templates, such as those in whole blood, of medium size and/or GC-rich, we found excellent performance of a PCR mix supplemented with 1 M 1,2-propanediol and 0.2 M trehalose (PT enhancer). These two additives together decreased DNA melting temperature and efficiently neutralized PCR inhibitors present in blood samples. They also made possible more efficient amplification of GC-rich templates than betaine and other previously described additives. Furthermore, amplification in the presence of PT enhancer increased the robustness and performance of routinely used qPCRs with short amplicons. CONCLUSIONS: The combined data indicate that PCR mixes supplemented with PT enhancer are suitable for DNA amplification in the presence of various DNA dyes and for a variety of templates which otherwise can be amplified with difficulty.
- MeSH
- DNA chemie genetika MeSH
- fluorescenční barviva chemie MeSH
- lidé MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- polymerázová řetězová reakce přístrojové vybavení MeSH
- propylenglykol chemie MeSH
- trehalosa chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Príspevok sa zaoberá skúmaním vplyvu bežne používaných humektantov glycerolu (GL) a propylénglykolu (PG) na liberáciu alaptidu (ALA) z 3% (m/m) chitosanových (CHIT) hydrogélov v porovnaní s liberáciou alaptidu (ALA) z krému. Obsah GL a PG v jednotlivých hydrogéloch bol 5 %, 10 %, 15 % (m/m). Alaptid je regeneračne pôsobiaci syntetický derivát prolyl-leucyl-glycin amidu, zatiaľ používaný vo veterinárnej medicíne. Jeho obsah v skúmaných hydrogéloch a kréme bol 1 % (m/m). Experimenty boli vykonané in vitro v temperovanej permeačnej aparatúre. Množstvo uvoľneného ALA bolo merané spektrofotometricky pri 212 nm, po 14. dňoch od prípravy jednotlivých chitosanových hydrogélov a krému. ALA sa uvoľnil v nasledovných množstvách: 14,06 % sa uvoľnilo z krému; 36,54 % z hydrogélu s obsahom 5 % GL (m/m); 37,85 % z hydrogélu s 5 % PG (m/m); 38,37 % z hydrogélu bez obsahu GL a PG; 40,71 % z hydrogélu s obsahom 15 % GL (m/m); 41,21 % z hydrogélu s 10 % GL (m/m); 42,72 % ALA sa uvoľnilo z hydrogélu s 10 % PG (m/m); 43,78 % z hydrogélu s 15 % PG (m/m). V závere možno usúdiť, že prítomnosť GL a PG malo vplyv na liberáciu ALA z dermálnych polotuhých liekov.
The paper examines the effects of routinely used humectants of glycerol (GL) and propylene glycol (PG) on the liberation of alaptid (ALA) from 3% (m/m) chitosan (CHIT) hydrogels in comparison with the liberation of alaptid (ALA) from cream. The contents of GL and PG in the individual hydrogels were 5%, 10%, 15% (m/m). Alaptid is a regeneratively acting synthetic derivative of prolyl-leucyl-glycin amide, which is for the time being used in veterinary medicine. Its content in the hydrogels and cream under study was 1% (m/m). The experiments were performed in vitro in a tempered permeating apparatus. The amount of the released ALA was measured spectrophotometrically at 212nm, 14 day after the preparation of the individual chitosan hydrogels and cream. ALA was liberated in the following amounts: 14.06% was released from cream; 36.54% from hydrogel containing 5% GL (m/m); 37.85% from hydrogel with 5% PG (m/m); 38.37% from hydrogel not containing GL and PG; 40.71% from hydrogel containing 15% GL (m/m); 41.21% from hydrogel with 10% GL (m/m); 42.72% ALA was released from hydrogel with 10% PG (m/m); 43.78% from hydrogel with 15% PG (m/m). It can be concluded that the presence of GL and PG exerted effects on liberation of ALA from dermal semisolid preparations.
