ABSTRACT
@#Polyethylene glycol (PEG) of different lengths were prepared to investigate their effects on oral absorption of nanostructured lipid carrier (NLCs).Three kinds of PEG-modified NLCs with different chain lengths, including polyethylene glycol (100) monostearate (S100), polyethylene glycol (55) monostearate (S55), polyethylene glycol (40) monostearate (S40), were prepared by film dispersion method.Coumarin 6 was chosen as a fluorescent probe to characterize the physicochemical properties of NLCs with different lengths.Meanwhile, the stability of NLCs in simulate buffer, the release behavior, cytotoxicity of NLCs, the uptake kinetics and cellular uptake mechanisms were evaluated. This work demonstrated that the thickness of the hydrated layer increased with the increase of PEG length. Of note, S100-modified NLCs (pNLC-EG100) exhibited higher cellular uptake efficiency compared with other formulations. Thus, S100 was optimized as the best molecular weight for PEG-modified NLCs on oral drug delivery system.
ABSTRACT
Objective: The sustained release curcumin solid lipid nanoparticles (Cur-SLN) and long circulating solid lipid nanoparticles (LSLN) were prepared, and the physicochemical properties of the two nanoparticles were investigated. Methods: Cur-SLN was prepared by emulsification ultrasonic method, and then the entrapment efficiency and drug loading of Cur-SLN prepared under the optimal formulation were determined. Cur-LSLN was prepared by back-extrapolation method, and the physicochemical properties of Cur-SLN and Cur-LSLN were evaluated by entrapment efficiency, drug loading, particle size, and Zeta potential; DSC was used to analyze, in vitro release characteristics and the transmission electron microscope (TEM) was used to observe particle appearance. Results: Based on the optimal conditions, TEM showed that the appearance of Cur-SLN and Cur-LSLN were spherical or nearly spherical, the entrapment efficiency respectively were (89.15 ± 0.66)% and (92.97 ± 0.27)%, drug loading were (1.72 ± 0.08)% and (1.98 ± 0.08)%, average diameters of particles were (144.5 ± 4.1) nm and (155.0 ± 2.6) nm, and the mean Zeta potential were (-23.6 ± 0.2) mV and (-47.8 ± 1.8) mV. Through DSC detection, it can be determined that Cur in nanoparticles had been transformed into amorphous state. In vitro release test showed that the drug release of the two preparations was divided into two stages: burst release phase and sustained released stage, the release rate was fast in 12 h, and the cumulative release of Cur-SLN in 96 h was 86.63%, and Cur-LSLN was 76.98%, so Cur-LSLN showed better sustained-release effect. Conclusion: Cur-SLN and Cur-LSLN can be successfully prepared by emulsification ultrasonic method, and PEG modified nanoparticles have better sustained-release properties and prolong the time of the presence of drug in vivo, providing reference for the development of targeted drugs.