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Objective To prepare dihydromyricetin (DMY) long-circulating liposomes and evaluate in vitro release dynamics and in vivo pharmacokinetics in rats. Methods Film-ultrasonic method was used to prepare DMY liposomes by single factor experiment and orthogonal test to optimize the formulation and preparation of DMY liposomes. The particle size and zeta potential of liposomes were determined by laser particle size analyzer. The morphological examination of liposomes was performed by using transmission electron microscopy. The liposome release in vitro was studied using dialysis method. DMY concentration in rat plasma was determined by the established LC-MS/MS method. Results The optimal prescription was 75∶20∶5 for soybean phospholipid-cholesterol-mPEG 2000-DSPE, and 1∶12 for DMY-lipid (wt/wt) with the ultrasonic time of 20 min and loading temperature of 60 ℃ in pH 5.0 PBS buffer. Under the optimized conditions, DMY liposomes was sphere with mean particle size of (117.9 ± 5.5) nm and mean zeta potential of (−2.6 ± 1.7) mV, the encapsulation efficiency and drug-loading content was (54.7 ± 3.3) % and (4.3 ± 0.2) %, respectively. The in vitro accumulative release rate of 48 h was 86% in pH 1.2 and pH 6.8 dissolve medium. Compared with free DMY, the t1/2z and AUC0-∞ of DMY liposome were increased by 2.7-fold and 1.8-fold, respectively. Conclusion Compared with free DMY, DMY liposomes released gently and slowly in vitro, eliminated slowly in vivo, and had higher bioavailability of oral administration.
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Objective To prepare quercetin liposome and to explore the antitumor effect of quercetin liposome.Methods The cholesterol and lecithin were used as membrane materials,quercetin nano liposome was prepared by thin film ultrasound method.The zeta potential and particle size distribution of quercetin liposome were tested by Malvern laser particle size analyzer and transmission electron microscope respectively.In order to explore the anti-tumor effect of quercetin nano-liposome,the mouse model of cervical cancer was established.After tail vein injection of quercetin and quercetin nano-liposome for 15 days,the tumor inhibitory rate,the thymus (spleen) index were analyzed,and the pathology of tumor tissues was further observed.Results Under the condition of lecithin∶cholesterol ∶ quercetin =8 ∶ 2 ∶ 1,the hydration time of 15 min and the ultrasonic time of 15 min,the quercetin nano-liposome was prepared,and the particle size distribution was uniform and the potential was-10.8.The tumor inhibitory rate of quercetin nano-liposome treatment group was 54.16％,which was significantly higher than that of the quercetin treatment group (x2 =6.477,P ＜ 0.05).The pathology results of the tumor tissues showed that nanocrystallization of quercetin could increase the anti-cancer effect of quercetin.Conclusion Both quercetin and quercetin nano-liposome exhibit significant effect on the tumor growth,and the inhibitory rate is increased after quercetin was nanocrystallization.Our study will provide theoretical basis for the application of quercetin nano-liposome in the treatment of cervical cancer.
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OBJECTIVE: To optimize the film-ultrasonic technique for preparing nicotinate-curcumin nanoparticles. METHODS: An HPLC method was established for determination of nicotinate-curcumin. Using the entrapment efficiency of nicotinate-curcumin as the evaluation indicator, the optimum excipient formula was selected through the Box-Bebnken reponse surface design of three factors (amounts of nicotinate-curcumin and lecithin and concentration of tween-80) at three levels. RESULTS: With the established optimal formula, ie 80 mg stearic acid, 150 mg lecithin and 20 mL tween-80 (0.6%), the entrapment efficiency of nicotinate-curcumin approached 65%. The mean particle size was 190 nm. CONCLUSION: The nicotinate-curcumin nanoparticles prepared by the film ultrasonic technique optimized by central composite design test have high entrapment efficiency, indicating that the technique is feasible.