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A new quercetin nanocrystals self-stabilized Pickering emulsion(QT-NSSPE) was prepared by high-pressure homogenization combined with probe ultrasonic method. The influences of oil fraction, quercetin(QT) concentration, and pH of water phase on the formation of QT-NSSPE were investigated. On this basis, the QT-NSSPE prepared under optimal conditions was evaluated in terms of microstructure, stability, and in vitro release and the droplet size and drug loading were 15.82 μm and 4.87 mg·mL~(-1), respectively. The shell structure formed by quercetin nanocrystals(QT-NC) on the emulsion droplet surface was observed under a scanning electron microscope(SEM). X-ray diffraction(XRD) showed that the crystallinity of adsorbed QT-NC decreased significantly as compared with the raw QT. There were not significant changes of QT-NSSPE properties after 30 days of storage at room temperature. The in vitro release experiment confirmed that QT-NSSPE has a higher accumulative release rate than the raw QT. All these results indicated that QT-NSSPE has a great stability and a satisfactory in vitro release behavior, which is a promising new oral delivery system for QT.
Subject(s)
Emulsions/chemistry , Nanoparticles , Particle Size , Quercetin , Water/chemistryABSTRACT
@#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： 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 establish a method for determining the content of tetracaine hydrochloride （TCH） ethosomes， and to optimize the preparation technology. METHODS： The content of TCH was determined by HPLC. TCH ethosomes were prepared with injection-ultrasonic method. Using drug-loading amount， egg lecithin concentration and ethanol volume fraction as factor， encapsulation efficiency as index， central composite design-response surface methodology was used to optimize the prescription based on the single factor test. The prepared ethosomes were characterized and the stability was evaluated. RESULTS： The linear range of TCH was 10-100 μg/mL （r＝0.999 5）； the limit of quantification was 0.045 μg/mL， and detection limit was 0.021 μg/mL. RSD of precision， stability and repeatability tests were less than 2％. The recoveries ranged 97.80％-103.20％ （RSD＝0.36％， n＝9）. The optimal preparation technology included that the adding amount of TCH control was 1 mg； the concentration of egg lecithin was 7 mg/mL， and ethanol volume fraction was 33％. Under this technology， the average encapsulation efficiency was 64.50％ （n＝3）， the relative error of which from the predicted value （64.92％） was 0.64％. TCH ethosome was a clear blue liquid with a blue opalescence. Its appearance was spherical， its shape was round， smooth， uniform in size； the average particle size was （80.33±2.24） nm， and the average Zeta potential was （－22.6±1.33） mV. TCH ethosome was stable during 10 days under 4 ℃， sealed and protected from light. CONCLUSIONS： The optimal preparation process is stable and feasible. Established method is simple and rapid.
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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 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.
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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 explore the effects of the process parameters of film dispersion-ultrasonic method on particle diameters and encapsulation efficiency of solid lipid nanoparticles of nicotinate-curcumin in order to obtain the process parameters resulting in smaller particle diameters and higher encapsulation efficiency .Methods: The content of nicotinate-curcumin was determined by HPLC.With the particle diameters and encapsulation efficiency of solid lipid nanoparticles of nicotinate -curcumin as the evaluation in-dicators , the process parameters of film dispersion-ultrasonic method were optimized by orthogonal experimental design and 95％confi-dence interval overlap method as the statistical analysis .Results:The optimum technological parameters of the solid lipid nanoparticles were as follows:the water bath temperature was 40℃and the rotation speed of eggplant bottle was 80 r· min-1 .The average particle size of solid lipid nanoparticles was 107.8 nm, polymer dispersity index ( PDI) was 0.583, and the encapsulation efficiency was 68.91％.Conclusion:The rotation speed of eggplant shaped bottle has notable influence on the particle diameters of solid lipid nanop -articles of nicotinate-curcumin prepared by film dispersion-ultrasonic method , while the water-bath temperature shows great influence on the encapsulation efficiency .Under the optimum conditions , it is possible to obtain the solid lipid nanoparticles with relatively smaller average particle diameters and higher encapsulation efficiency .
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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.
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Objective:To prepare vascular endothelial growth factor receptorⅡ ( VEGFRⅡ)-mediated targeted sulphur hexafluo-ride microbubble image agent and evaluate its targeting ability in human breast cancer MCF-7 in vitro. Methods:The sulphur hexafluo-ride microbubble image agent was prepared by a membrane dispersion-ultrasonic method and optimized by Box-Behnken design using design-expert 8. 0. 6 software. VEGFRⅡ-mediated targeted microbubble image agent was prepared by an absorption method. VEGFRⅡ-mediated targeted microbubble image agent was characterized by the morphology, particle size distribution and zeta potential. The targeting ability of the image agent in human breast cancer MCF-7 in vitro was detected by an immunofluorescent assay. Results:The particle size, polydispersion index and zeta potential of VEGFRⅡ-mediated targeted microbubble image agent was (3. 81 ± 0. 32) μm, 0. 261 ± 0. 037 and ( -25. 7 ± 2. 8) mV, respectively. The microbubbles were small and spherical with smooth surface as seen under a transmission electron microscope. VEGFRⅡ-mediated targeted microbubble image agent could combine with human breast cancer MCF-7 specifically in vitro. Conclusion: The absorption preparation technology of the targeted microbubble image agent is feasible, and the microbubble image agent has strong and especial targeting function in vitro.
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Objective: With nonionic surfactants as the carrier material to prepare glycyrrhetinic acid (GC) niosomes (NI) and to evaluate the quality. Methods: The thin film dispersion-ultrasound method was used for establishing the preparation process of GC - NI, reverse dialysis method and ultraviolet spectrophotometer method were used to determine the encapsulation efficiency (EE), the prescription and preparation process were optimized through single factor and central composite design-response surface methodology (CCD-RSM), and the properties of morphology, particle size, Zeta potential, and EE in optimized NI were investigated. Results: The optimum prescription process as Span 80-cholesterol was 2:1, hydration temperature was 70℃, hydration time was 51 min, ultrasonic time was 60 min, its forecast EE was 80.66%, bias between the observed and predicted values was 4.95%, and regression coefficient of binomial fitting complex model was as high as 0.989 9. Conclusion: CCD-RSM is used to optimize the preparation, which has the stable, feasible, high precision, and good predictability advantage.
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Objective To prepare drug carrier non-PEG blank liposomes, and study its properties.Methods High purity of egg yolk lecithin and cholesterol were used as film forming material.The high pressure homogeneous method-extrusion method and high pressure homogeneous method-ultrasonic method were used to prepare non-PEG blank liposomes.After that how the method of high pressure homogeneous, extrusion and ultrasonic influence the particle size of blank liposomes were studied, and the physical stability of blank liposomes were investigated.ResuIts The particle size of blank liposomes prepared by high pressure homogeneous method-extrusion method was about 86 nm, and its polydispersity index was 0.170.While the particle size of the blank liposomes prepared by high pressure homogeneous method-ultrasonic method was about 91 nm, and its polydispersity index was 0.362.ConcIusion Compared with high pressure homogeneous method-ultrasonic method, the blank liposomes prepared by high pressure homogeneous method-extrusion method had some advantanges, such as smaller particle size, narrow particle size distribution and high stability.
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Objective: To prepare paeoniflorin lipid liquid crystalline nanoparticles (Pae-LLCN), and to study its in vitro release behavior. Methods: Using encapsulation efficiency (EE) as index, the Pae-LLCN were prepared by spontaneous emulsification and ultrasonic method, and the prescription of Pae-LLCN was optimized by orthogonal design. The in vitro release of Pae-LLCN within 24 h was measured by dialysis method, afterwards its morphology and particle size were studied by transmission electron microscope (TEM). Results: The optimal formulation was poloxamer-glycerol monooleate (1∶10), paeoniflorin inventory (40 mg), and PBS solution (20 mL). The average EE was 73.72%, the average DL was 14.81%, the size of nanoparticles was (170 ± 16) nm, and the 24 h in vitro accumulative release rate was 72.68%. Conclusion: The optimized process is rational and feasible, and the Pae-LLCN has good stability with better sustained release in vitro.
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Objective: To study three different extraction processes of the content of total flavonoids in Chrysanthemum indicum and their anti-oxidant activities. Methods: The reflux, ultrasonic, and tissue-breaking methods were used for extracting the total flavonoids from C. indicum, which were determined by UV spectrophotometry, and the anti-oxidant activity was determined by flow injection chemiluminescence. Results: The contents of total flavonoids obtained using various methods, such as reflux, ultrasonic, and tissue- breaking, were 12.60, 11.02, and 10.95 mg/g, and their IC50 were 2.67, 3.43, and 5.13 μg/mL, respectively. Conclusion: The research indicates that the reflux extraction method is applied to isolatting the total flavonoids from C. indicum, with the advantage of high extraction efficiency, and the total flavoniods show the strong anti-oxidant activity.
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Objective: To establish an HPLC method for the fingerprint analysis of Aquilariae Resinatum Lignum (ARL), so as to provide evidence for the identification and quality control of ARL. Methods: The analysis was carried out on a Dionex-Acclaim 120 C18 column (250 mm × 4.6 mm, 5 μm). The mobile phase consisted of acetonitrile and water-acetic acid (99.5:0.5) with the flow rate of 0.4 mL/min at 254 nm and the separation was performed at 26℃. The similarity was analyzed with "Similarity Evaluation System for Chromatographic Fingerprint of Chinese Materia Medica 2004A" and the cluster analysis was performed by SPSS software. Results: The HPLC characteristic fingerprint of ARL has been established. A total of 24 common peaks were characterized, and nine of them were identified by comparing their retention time with reference subslances. The values of similarity evaluation mostly agreed with the result of cluster analysis. Conclusion: It is the first time to establish the HPLC fingerprint of ARL. The method is simple and quick, and reflects the information of chemical composition of ARL comprehensively, which provides the scientific basis for the identification and quality evaluation of ARL.
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OBJECTIVE:To compare the ultrasound method and continuous reflux extraction process of total flavonoids from Radix Astragali.METHODS:The extraction technology was optimized by orthogonal test with the content of total flavonoids of Radix Astragali as index and with the concentration of ethanol,extraction time,solid-fluid ratio,extraction temperature as factors.RESULTS:Ultrasound extraction process was superior to continuous reflux extraction process.Optimal extraction technology was as follows:the concentration of ethanol of 75%,ultrasonic extraction time of 20 min,solid-liquid ratio of 1:10,ultrasonic extraction temperature of 25 ℃ and extraction rate of 0.325%.CONCLUSION:As compared with continuous reflux extraction process,ultrasonic extraction is fast to operate,solvent saving and high extraction.
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OBJECTIVE:To optimize the extraction conditions of total flavones from Pueraria Lobata by ultrasonic method.METHODS:The uniform design method was applied to investigate the effects of alcohol content,the quantity of solvent,extraction time,extraction temperature and the extraction times on the result of extraction.The content of total flavone of Pueraria Lobata was determined by ultraviolet-visible spectrophotometry.The extraction conditions were optimized with the extraction yield and the mass fraction of total flavone of Pueraria lobata in the extract as indexes.RESULTS:The optimal extraction conditions were as follows:extracting with 75% alcohol(20 mL?g-1) for 40 min(extraction time) at 68 ℃(extraction temperature) for a total of 5 times.CONCLUSION:The extraction process is reasonable and feasible and it provides theoretic basis for the industrialized production.