To increase the solubility and adsorption of budesonide（BUD）,budesonide-loaded solid lipid nanoparticles（BUD-SLNs） were prepared and characterized in this study.Glycerin monostearate（GMS）was selected to be the matrix lipid material after calculation the differences of partial solubility parameters.An emulsification-ultrasound diffusion method was employed and formula was optimized in the BUD-SLNs preparation.The entrapment efficiency（ee%）of BUD-SLNs was（97.77±2.60）%, and the mean particle size was 147.3 nm（PDI=0.228）.Uniform and sphere particles were observed under TEM.The in vitro release of BUD-SLNs could be well explained by the biphasic release dynamics equation.The spectrums of DSC and X-ray diffraction indicated that BUD molecules were dispersed mainly into the lipids to form homogeneous matrix structure.Our results provide fundamental data for the application of SLNs in pulmonary delivery system.
We investigated the bio-distributions of [125 I]Spiro-I formulated in sterically stabilized liposomes （SSL） or targeted liposomes （SSTL） in mice,especially their brain uptake.The [125 I]Spiro-I liposomes were prepared by film-ultrasound dispersion method.Cereport （RMP-7） was covalently conjugated with DSPE-PEG,which was attached to the surface of SSL to form SSTL.The encapsulation efficiencies （ee%） of [125 I]Spiro-I-SSL and [125 I]Spiro-I-SSTL were 97.47%±4.01% and 93.02%±2.98%,respectively.The average particle sizes were （66.47±0.76） nm and （71.40±0.45） nm,respectively.After intravenous administration,[125 I]Spiro-I was quickly eliminated from blood.SSL could prolong the retention time of [125 I]Spiro-I in blood and SSTL improved its brain uptake.The AUC of [125 I]Spiro-I-SSTL in brain was increased by 1.52 times as compared to [125 I]Spiro-I,indicating that SSTL could be used for the formulation of [125 I]Spiro-I for the imaging of central nervous system （CNS）.
