ABSTRACT
This study aims to improve the solubility and bioavailability of daidzein by preparing the β-cyclodextrin-daidzein/PEG_(20000)/Carbomer_(940) nanocrystals. Specifically, the nanocrystals were prepared with daidzein as a model drug, PEG_(20000), Carbomer_(940), and NaOH as a plasticizer, a gelling agent, and a crosslinking agent, respectively. A two-step method was employed to prepare the β-cyclodextrin-daidzein/PEG_(20000)/Carbomer_(940) nanocystals. First, the insoluble drug daidzein was embedded in β-cyclodextrin to form inclusion complexes, which were then encapsulated in the PEG_(20000)/Carbomer_(940) nanocrystals. The optimal mass fraction of NaOH was determined as 0.8% by the drug release rate, redispersability, SEM morphology, encapsulation rate, and drug loading. The inclusion status of daidzein nanocrystals was determined by Fourier transform infrared spectroscopy(FTIR), thermogravimetric analysis(TGA), and X-ray diffraction(XRD) analysis to verify the feasibility of the preparation. The prepared nanocrystals showed the average Zeta potential of(-30.77±0.15)mV and(-37.47±0.64)mV and the particle sizes of(333.60±3.81)nm and(544.60±7.66)nm before and after daidzein loading, respectively. The irregular distribution of nanocrystals before and after daidzein loading was observed under SEM. The redispersability experiment showed high dispersion efficiency of the nanocrystals. The in vitro dissolution rate of nanocrystals in intestinal fluid was significantly faster than that of daidzein, and followed the first-order drug release kinetic model. XRD, FTIR, and TGA were employed to determine the polycrystalline properties, drug loading, and thermal stability of the nanocrystals before and after drug loading. The nanocrystals loaded with daidzein demonstrated obvious antibacterial effect. The nanocrystals had more significant inhibitory effects on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa than daidzein because of the improved solubility of daidzein. The prepared nanocrystals can significantly increase the dissolution rate and oral bioavailability of the insoluble drug daidzein.
Subject(s)
Sodium Hydroxide , Acrylic Resins , Escherichia coli , NanoparticlesABSTRACT
Objective To investigate the effect of the bletilla striata polysaccharide on the expression of ovarian vascular endothelial growth factor(VEGF) and serum malondialdehyde(MDA)and endometrial morphology in rat during perimenopause period.Methods The animal model of perimenopause rats was established by unforced aging.A total of 40 female SD rats(12~14 months old)were randomly divid-ed into four groups:Chinese medicine low(0.5 g/kg),medium(1 g/kg),high(2 g/kg) dosage group and the elder model group.The rats were given with corresponding drugs for 8 weeks.The content changes of ovarian VEGF protein was detected by western blot;serum MDA con-tent was detected by thiobarbituric acid;the morphology of endometrium in rats was observed by HE staining.Results Eight weeks later, compared with the elder model group,the VEGF protein expression in Chinese medicine low,medium,high dosage group increased,the serum MDA content in Chinese medicine low,medium,high,dosage group reduced,the differences were statistically significant( P<0.01),with dose dependence.Endometrial thickening and glandular increasing with the increase of dose.Conclusion Bletilla striata polysaccharide can upregulate the expression of VEGF protein,and down regulate the level of serum MDA,which improves the uterine function so as to delay the process of perimenopause in rats.