Résumé
This study investigated the effect of different carrier materials on the in vitro properties of progesterone solid dispersions. The solid dispersions of the insoluble drug progesterone were prepared by hot melt extrusion technique using rheological properties as the index of investigation, and the in vitro properties of the solid dispersions were characterized. Scanning electron microscope revealed solid dispersions with rough surfaces and agglomerated microstructures into irregular lumpy particles. Differential scanning calorimetry and powder X-ray diffraction showed the change of progesterone crystalline form in solid dispersions from crystalline to amorphous state. In vitro dissolution studies showed that solid dispersions prepared with different carrier materials can effectively improve the dissolution rate of drugs. The results of the study showed that the type of carrier material had a significant effect on the in vitro properties of solid dispersions, providing a reference for the study of solid dispersions in the controlled release of insoluble drugs.
Résumé
<p><b>OBJECTIVE</b>To study the effects of Weipixiao (胃痞消, WPX) on Wnt pathway-associated proteins in gastric mucosal epithelial cells from rats with gastric precancerous lesions (GPL).</p><p><b>METHODS</b>Sprague Dawley rats were randomly divided into control, model, vitacoenzyme (0.2 g·kg(-1)·day(-1)), WPX high-dose (H-WPX, 15 g·kg(-1)·day(-1)), WPX medium-dose (M-WPX, 7.5 g·kg(-1)·day(-1)) and WPX low-dose (L-WPX, 3.75 g·kg(-1)·day(-1)) groups. After successfully establishing the GPL model, the rats were consecutively administered WPX or vitacoenzyme by gastrogavage for 10 weeks. Differential expression of Leucine-rich repeat-containing G-proteincoupled receptor 5 (Lgr5), matrix metalloproteinase-7 (MMP-7), Wnt1, Wnt3a, and β-catenin in gastric mucosal epithelial cells in all groups were immunohistochemically detected, and the images were taken and analyzed semiquantitatively by image pro plus 6.0 software.</p><p><b>RESULTS</b>Gastric epithelium in the model group showed significantly higher expression levels of Lgr5, MMP-7, Wnt1, Wnt3a and β-catenin than those of the control group(P<0.01). Interestingly, we also observed Lgr5+ cells, which generally located at the base of the gastric glandular unit, migrated to the luminal side of gastric epithelium with GPL. The expression levels of Lgr5, MMP-7, Wnt1, and β-catenin were all down-regulated in the L-WPX group as compared with those of both model and vitacoenzyme groups (P<0.05). A similar, but nonsignificant down-regulation in expression level of Wnt3a was noted in all WPX groups (P>0.05).</p><p><b>CONCLUSION</b>Our findings suggested that the therapeutic mechanisms of WPX in treating GPL might be related with its inhibitory effects on the expressions of Lgr5, MMP-7, Wnt1, β-catenin and the aberrant activation of Wnt/β-catenin pathway.</p>