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@#To prepare and optimize luteolin nanostructured lipid carriers (Lut-NLCs) and investigate their antibacterial activity in vitro. Lut-NLCs were prepared by hot melt emulsification-ultrasonic method. The solid lipid concentration (X1),liquid lipid concentration (X2) and surfactant concentration (X3) were used as independent variables,with the average particle size (Y1) and the encapsulation efficiency (Y2) as the dependent variables. The optimal formulation of Lut-NLCs was obtained through Box-Behnken experiment design. The microstructure of Lut-NLCs was observed by transmission electron microscopy(TEM). The in vitro release characteristics of Lut-NLCs were investigated. Furthermore, the in vitro antibacterial activities of luteolin and Lut-NLCs were compared. The formulation composition of Lut-NLCs was optimized as follows:the concentration of the solid lipid, liquid lipid and surfactant were 13.0 mg/mL,15.0 mg/mL,and 15.0 mg/mL,respectively. Three batches of Lut-NLCs were prepared with an average particle size of (210.4±17.3) nm,and an encapsulation efficiency of (88.4±1.2)%. Lut-NLCs were observed to be spheroidal,with a smooth surface and a uniform particle size distribution by TEM. The drug release profiles of Lut-NLCs showed a bursting release in the early stage and a slow and stable release in the later stage. Moreover, the cumulative release amount of drug reached 95% in 12 hours. The results of antibacterial circle experiment showed that the antibacterial effect of Lut-NLCs on Staphylococcus aureus and Escherichia coli was higher than that of luteolin raw materials. In this study,the formulation of Lut-NLCs prepared by simple preparation process is reasonable,and Lut-NLCs also exhibited the significant in vitro antibacterial activity. It is expected to be an effective way for external application of luteolin.
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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.
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OBJECTIVE： To optimize the preparation technology of Celastrol nanostructured lipid carriers （Cel-NLC）， and to characterize it. METHODS： Cel-NLC was prepared by melt-emulsification ultrasonic method. Based on single factor test， using encapsulation rate of Cel as index， the ratio of liquid lipid （the ratio of total mass）， the amount of compound emulsifier and the dose of main drug were optimized by central composite design-response surface methodology. Validation test was conducted. Zeta potential and particle size of Cel-NLC that prepared by optimal prescription were determined by using granularity and Zeta potential analyzer. The morphology of liposome was observed by TEM. RESULTS： The optimal prescription included that the ratio of liquid lipid was 39％；the amount of compound emulsifier was 196 mg；the dose of main drug was 8 mg. The average encapsulation efficiency of 3 batches of Cel-NLC was 87.22％； average particle size was （41.2±1.1） nm，and average Zeta potential was （－18.4±0.2） mV （n＝3）. It was spherical under electron microscopy. CONCLUSIONS： The optimized technology is simple， stable and feasible， and it is suitable for the preparation of Cel-NLC.
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Objective To optimize the prescription and preparation technology of brucine nanostructured lipid carriers (B-NLC). Methods The method of "the solvent emulsification ultrasound" was used to prepare B-NLC. The prescription and preparation was optimized using a single factor method combined with central composite design-response surface methodology (CCD-RSM). Results The resultant B-NLC was transparent liquid with light blue opalescence. The optimal conditions were that the dosage of drugs was 1.28 mg, the mass concentration of poloxamer 188 was 1.08%, and the ratio of solid lipid to liquid lipid was 1.45:1. The obtained NLC showed the average particle size of (136.89 ± 4.23) nm with a polydispersity index of 0.289 ± 0.005 and a zeta potential of (-34.46 ± 0.31) mV. The entrapment efficiency was calculated to be (68.98 ± 2.06)%, and the drug loading content was (1.90 ± 0.06)%. Conclusion B-NLC prepared by solvent emulsification ultrasound had a high entrapment efficiency and a narrow particle size distribution. The method was easy and simple and can be used to optimize the prescription and preparation of B-NLC, which provides a foundation for the further in vivo research of brucine.
