ABSTRACT
<p><b>AIM</b>To perpare and identify irisquinone hydroxypropyl-beta-cyclodextrin inclusion complex (irisquinone-HP-beta-CD), as well as to study the inclusion mechanism and molecule stoichiometry between irisquinone and hydroxypropyl-beta-cyclodextrin.</p><p><b>METHODS</b>Irisquinone-HP-beta-CD was prepared by freeze-drying technique. The ratio of host and guest was also studied in inclusion process by mol gradient and continuing variational methods. At the same time, the inclusion complex was identified by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).</p><p><b>RESULTS</b>It was demonstrated that the solubility of irisquinone was enhanced markedly by inclusion with HP-beta-CD when stoichiometry was 2:1 of host and guest at 25 degrees C, 35 degrees C and 45 degrees C.</p><p><b>CONCLUSION</b>The solubility and stability of irisquinone could be increased by preparing the inclusion complex with hydroxypropyl-beta-cyclodextrin.</p>
Subject(s)
2-Hydroxypropyl-beta-cyclodextrin , Benzoquinones , Chemistry , Calorimetry, Differential Scanning , Drug Compounding , Methods , Drug Stability , Freeze Drying , Solubility , X-Ray Diffraction , beta-Cyclodextrins , ChemistryABSTRACT
<p><b>AIM</b>To investigate the permeation mechanism of paclitaxel by enhancers and preparation factors.</p><p><b>METHODS</b>The fluidity of mucous membrane and membrane protein conformation changes were determined by using electron spin resonance (ESR) when mucous membrane was treated by several enhancers. At the same time, the factors of penetration of lower dissolution drug across the intestinal mucous membrane were studied in three formulas inclusion complex, microemulsion and injection.</p><p><b>RESULTS</b>Polyethylene glycol (PEG) 1500, hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and phospholipid as enhancers could reinforce the permeation of paclitaxle because of loosening of protein conformation in intestinal mucous membrane. Paclitaxel-HP-beta-CD inclusion complex and paclitaxel microemulsion as vehicle could significantly increased permeation kinetic rate of paclitaxel with fluid diffuse method.</p><p><b>CONCLUSION</b>Characteristics of enhancing intestinal absorption of poor dissolution drug had been provided with enhancer the change of membrane fluid.</p>
Subject(s)
Animals , Rats , 2-Hydroxypropyl-beta-cyclodextrin , Antineoplastic Agents, Phytogenic , Pharmacokinetics , Drug Synergism , Electron Spin Resonance Spectroscopy , Emulsions , Injections , Intestinal Absorption , Intestinal Mucosa , Membrane Fluidity , Paclitaxel , Pharmacokinetics , Pharmaceutical Vehicles , Pharmacology , Phospholipids , Pharmacology , Polyethylene Glycols , Pharmacology , Rats, Sprague-Dawley , beta-Cyclodextrins , PharmacologyABSTRACT
<p><b>AIM</b>To investigate the absorption and distribution of recombinant hirudin-2 (rHV2) in the GI tract in rats after oral administration.</p><p><b>METHODS</b>Using HPLC, fluorescence spectrophotometry and confocal laser scanning microscopy to measure the amount of intact rHV2 absorbed into gastrointestinal mucosa and blood.</p><p><b>RESULTS</b>HPLC spectrum showed that there were intact rHV2 molecules in plasma after 1 h of oral administration. After oral administration for 3 h, 1.2%-26.8% of fluorescence was found in the GI tract in rats. Chromatographic analysis showed that 2.27%-38.75% of fluorescence recovered from the GI tract luminal contents and mucosa was eluted at the void volume of a Sephadex G-25 column. Microscopic examination showed that FITC-rHV2 was taken up throughout the whole small intestine but the ileum appeared to be a preferred site for FITC-rHV2 transport in rats.</p><p><b>CONCLUSION</b>rHV2 may partially survive in the GI lumen and subsequently absorbed in active form by gastrointestinal tract.</p>