The effect of cetyl palmitate crystallinity on physical properties of gamma-oryzanol encapsulated in solid lipid nanoparticles

This present study was aimed at investigating the effect of the crystallinity of cetyl palmitate based solid lipid nanoparticles (SLNs) on the physical properties of γ-oryzanol-loaded SLNs. SLNs consisting of varying ratios of cetyl palmitate and γ-oryzanol were prepared. Their hydrodynamic diameters were in the range 210-280?nm and the zeta potentials were in the range -27 to -35?mV. The size of SLNs increased as the amount of cetyl palmitate decreased whereas no significant change of zeta potentials was found. Atomic force microscopy pictures indicated the presence of disc-like particles. The crystallinity of SLNs, determined by differential scanning calorimetry and powder x-ray diffraction, was directly dependent on the ratio of cetyl palmitate to γ-oryzanol and decreased with decreasing cetyl palmitate content in the lipid matrix. Varying this ratio in the lipid mix resulted in a shift in the melting temperature and enthalpy, although the SLN structure remained unchanged as an orthorhombic lamellar lattice. This has been attributed to a potential inhibition by γ-oryzanol during lipid crystal growth as well as a less ordered structure of the SLNs. The results revealed that the crystallinity of the SLNs was mainly dependent on the solid lipid, and that the crystallinity has an important impact on the physical characteristics of active-loaded SLNs.     

Preparation and characterization of camptothecin solid lipid nanoparticles

Camptothecin (CA), an antitumor drug, was incorporated into solid lipid nanoparticles (SLNs) prepared by high-pressure homogenization. A Taguchi orthogonal experimental design was used to study the influence of four different variables, with each variable having three value levels on nanoparticle size. Analysis of variance (ANOVA) has been used to evaluate the preparation of CA-SLNs and perform product optimization. The optimized CA-SLNs suspension was lyophilized using mannitol and glucose as cryoprotectants. The physicochemical characteristics of CA-SLNs were evaluated using transmission electron microscopy (TEM), electrophoresis, and differential scanning calorimetry (DSC). The release of camptothecin from CA-SLNs in various media was evaluated using a high-performance liquid chromatography (HPLC) method. The results showed that the concentration of emulsifier and the homogenization pressure had a significant influence on the particle size. The optimized CA-SLNs had an average diameter of about 200 nm, exhibited monodispersity with Dw/Dn of 1.06, and carried a negative charge. The optimal cryoprotectants consisted of 10% mannitol and 5% glucose in nanoparticle suspension. Lyophilized product was reconstituted in distilled water within 0.5 min without change of nanoparticle size. Camptothecin might exist in an amorphous state in SLNs. In vitro results showed that drug release was achieved for up to one week, and the released camptothecin quickly changed to open carboxylate form in the biological pH phosphate buffer. The results indicate that SLNs might be good potential sustained-release delivery vehicles for camptothecin or other lipophilic drugs.     

The formulation and delivery of curcumin with solid lipid nanoparticles for the treatment of on non-small cell lung cancer both in vitro and in vivo

Curcumin was determined to have anticancer potency on several kinds of carcinoma. However, its medical application was limited because of its poor bioavailability, unsatisfying dispersity and rapid metabolism in vivo. In this study, curcumin was delivered by solid lipid nanoparticles (SLN) for lung cancer treatment. The physiochemical characters of SLN-curcumin were detected by HPLC, TEM, Zeta potential analysis and FTIR, and the anticancer efficiency on lung cancer was determined both in vitro and in vivo. SLN-curcumin was synthesized by sol–gel method with the size ranged from 20 to 80 nm. After being loaded in SLN, the IC₅₀ of SLN-curcumin on A549 cells was 4 μM, only 1/20 of plain drug. The plasmid concentration of curcumin was highly increased in mice via i.p. after loaded with SLN. Furthermore, SLN-curcumin enhanced the targeting of curcumin to lung and tumor, which finally increased the inhibition efficiency of curcumin from 19.5% to 69.3%. The Flow Cytometry (FCM) analysis and immuno staining confirmed that the inhibition effect mostly came from apoptosis, but not necrosis. The tumor targeting and profound tumor inhibition effect of SLN-curcumin indicated its medical application on lung cancer treatment, and also provided a novel method for new anticancer agents' development.     

Solid lipid nanoparticles of anticancer drug andrographolide: formulation,in vitro and in vivo studies

Diterpenoidal anti-cancer drug andrographolide (AD) was encapsulated into solid lipid nanoparticle (SLN) because of poor aqueous solubility and high lipophilicity. AD-SLNs were prepared by solvent injection method and characterized for droplet size, surface morphology, zeta potential, etc. In vitro drug release was carried out by dialysis-membrane method. A pharmacokinetic study was performed by UPLC/Q-TOF-MS method to determine the maximum plasma concentration (C_max), area under the curve (AUC), etc. There was an improvement in C_max and AUC of AD-SLNs when compared with AD, thereby enhancing the bioavailability of AD. The t_max was increased than that of AD suspension, indicating the sustained release pattern of AD-SLNs. The antitumor activity was carried out on Balb/c mice showing better results with AD-SLNs as compared to AD. Thus, the AD-loaded SLNs would be useful for delivering poorly water-soluble AD with enhanced bioavailability and improved antitumor activity.     

In vitro evaluation of idebenone-loaded solid lipid nanoparticles for drug delivery to the brain

Context: Solid lipid nanoparticles (SLN) are regarded as interesting drug delivery systems and their preparation techniques have gained a great deal of attention.

Objective: To evaluate the feasibility of preparing idebenone (IDE) loaded SLN from O/W microemulsions by the phase-inversion temperature (PIT) method. Since SLN have been proposed to improve drug delivery to the brain, IDE was chosen as model drug due to its activity in the treatment of neurodegenerative diseases.

Materials and Methods: Cetyl palmitate was used as solid lipid to prepare SLN containing two surfactant/cosurfactant mixtures, isoceteth-20/glyceryl oleate (SLN A) and ceteth-20/glyceryl oleate (SLN B) by the PIT method.

Results and discussion: All the formulations tested showed a mean particle diameter ranging from 30 to 95?nm and a single peak in size distribution. Stability tests showed that SLN B were more stable than SLN A. IDE release was dependent both on the type of primary surfactant used and the amount of loaded drug. IDE-loaded SLN were effective in inhibiting 2,2′-azobis-(2-amidinopropane)dihydrochloride (APPH)-induced lactic dehydrogenase (LDH) release and reactive oxygen species (ROS) production in primary cultures of astrocytes obtained from rat cerebral cortex. It is noteworthy that SLN B2 (containing ceteth-20 as primary surfactant and 0.7% w/w IDE) were able to prevent entirely both the LDH release and ROS production induced by APPH.

Conclusion: The PIT method provided SLN with good technological properties. The tested SLN could be regarded as interesting carriers to overcome the blood brain barrier and increase the efficacy of the loaded drug.     

Topical delivery of tetrahydrocurcumin lipid nanoparticles effectively inhibits skin inflammation: in vitro and in vivo study

Tetrahydrocurcumin (THC) also referred to as ‘white curcumin’, is a stable colorless hydrogenated product of curcumin with superior antioxidant and anti-inflammatory properties. The present study is an attempt to elevate the topical bioavailability of THC, post-incorporation into a nano-carrier system with its final dosage as a hydrogel. Lipid nanoparticles of THC (THC-SLNs) prepared by microemulsification technique were ellipsoidal in shape (revealed in transmission electron microscopy) with a mean particle size of 96.6?nm and zeta potential of ?22?mV. Total drug content and entrapment efficiency of THC-SLNs was 94.51%?±?2.15% and 69.56%?±?1.35%, respectively. Differential scanning calorimetry and X-ray diffraction studies confirmed the formation of THC-SLNs. In vitro drug release studies showed the drug release from THC-SLNs gel to follow Higuchi’s equation revealing a Fickian diffusion. Ex vivo permeation studies indicated a 17 times (approximately) higher skin permeation of THC-SLNs gel as compared with the free THC gel. Skin irritation, occlusion, and stability studies indicated the formulation to be nonirritating, and stable with a desired occlusivity. Pharmacodynamic evaluation in an excision wound mice model clearly revealed the enhanced anti-inflammatory activity of THC-SLNs gel and was further confirmed using biochemical and histopathological studies. It is noteworthy to report here that THC-SLNs gel showed significantly better (p?≤?0.001) activity than free THC in gel. As inflammation is innate to all the skin disorders, the developed product opens up new therapeutic avenues for several skin diseases. To the best of our knowledge, this is the first paper elaborating the therapeutic usefulness of white curcumin-loaded lipidic nanoparticles for skin inflammation.     

Preparation,characterization, cellular uptake and evaluation in vivo of solid lipid nanoparticles loaded with cucurbitacin B

In this work, solid lipid nanoparticles loaded with cucurbitacin B (Cu B-SLNs) were prepared. It was found that the concentration of poloxamer 188 and soybean lecithin had effects on the mean particle size and size distribution. The zeta potentials were around ?33 mV. In vitro release studies showed a sustained release after a burst release. Internalization of Cu B into HepG2 cells could be enhanced by the encapsulation of SLN matrix. The IC50 values of Cu B-SLNs were lower than that of Cu B solution. Both free Cu B and Cu B-SLNs had effectively inhibited the tumor growth and displayed a dose-dependent anti-tumor efficacy. Cu B-SLNs at a dose of 0.11?mg/kg produced the greatest anti-tumor effects (53.3%), which was significant higher than Cu B solution (31.5%, p < 0.05). Cu B-SLNs showed a longer MRT in vivo. The AUC of Cu B-SLNs for tumor increased 3.5 –fold when compared to Cu B solution. The targeting efficiency of Cu B-SLNs was 1.94 times higher in liver as compared to that of Cu B solution. These results indicated that Cu-B SLNs could passively target the tumor with EPR effect, improve the therapeutic efficacy of Cu B, and reduce the doses.     

Preparation,optimization, characterization and in vivo pharmacokinetic study of asiatic acid tromethamine salt-loaded solid lipid nanoparticles

Purpose: To enhance the oral bioavailability of asiatic acid tromethamine salt (AAS) by encapsulation in solid lipid nanoparticles (SLN).

Methods: The AAS-loaded SLN (AASLN) was prepared by the modified solvent injection method with glycerin monostearate (GMS) as lipid and poloxamer 188 as surfactant. A Box–Behnken design was used to optimize the formulations. Physicochemical characterization was carried out by using dynamic light scattering, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Stabilities at 4?°C and pH 1.2 were investigated by particle size or/and entrapment efficiency (EE%). The in vivo pharmacokinetics was evaluated by HPLC-MS/MS.

Results: The optimal formulation of AASLN had an average size of 237?nm with zeta potential of ?35.9?mV, and EE% of 64.4%. SEM showed that the AASLN had spherical shape with smooth surface. Furthermore, DSC and X-ray analyses indicated that AAS was amorphous state and the crystal degree of GMS was significantly decreased in the formulation. AASLN showed excellent stability at 4?°C for 1 month and no coacervation at pH 1.2. The bioavailability of AAS in SLN was found to be 2.5-fold higher than that of AAS alone after a single oral administration in rats.

Conclusions: This study reveals that SLN is developed as a promising oral delivery system of AAS with significantly enhanced bioavailability and good storage stability.     

Preparation and characterization of solid lipid nanoparticles of furosemide using quality by design

The present work aimed to synthesize solid lipid nanoparticles (SLNs) of Furosemide (FRSM). The parameter sensitivity analysis showed a significant effect of particle size and reference solubility on the AUC_0–∞, C_max and t_max. The FRSM-encapsulated SLNs were synthesized by the phase inversion temperature (PIT) technique using 3² factorial design. The optimal level of 221.28?mg of Compritol 888 ATO and 420?mg of Cremophor RH 40 showed a mean hydrodynamic diameter (MHD) of 25.54?±?0.57?nm, a polydispersity index (PdI) of 0.158?±?0.01, the % entrapment efficiency of 80.70?±?4.06%, percent dissolution efficiency of 71.72?±?1.52% and time elapsed for 50% drug release of 3.67?±?0.15?h. The PIT was determined using the turbidity method and the values ranged between 75°C and 73°C. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) images represent spherical to sub-spherical and smooth surface of SLN. The Fourier transform-infrared (FTIR), differential scanning calorimetry (DSC) and x-ray diffraction (XRD) depict the drug-excipient compatibility. Korsmeyer–Peppas was found to be the best fit release kinetics model (R²?=?0.973; K-value?=?29.96 and release exponent?=?0.40), predicting the Fickian diffusion. The results advocate that the optimized formulation (OF) could promote the controlled release, and improve the physicochemical stability of the formulation. Hence, SLN could be a potential drug carrier for the peroral delivery of FRSM.     

In vitro evaluation on a model of blood brain barrier of idebenone-loaded solid lipid nanoparticles

The aim of this study was to evaluate in vitro the permeation of the antioxidant agent Idebenone (IDE) loaded into solid lipid nanoparticles (SLN) across MDCKII-MDR1 cell monolayer, selected as an in vitro model of the Blood Brain Barrier (BBB). SLN were prepared using cetyl palmitate as solid lipid and different non-ionic surfactants, oleth-20, ceteth-20 and isoceth-20, by the phase inversion temperature (PIT) technique. The resulting SLN showed physiological pH and osmolarity values, a mean particle diameter in the range of 33-63 nm, a single peak in size distribution, and a zeta potential ranging from +3.14 to -2.89 mV. When incubating these SLN in Simulated Body Fluid (SBF), the particle size was maintained for all samples throughout the study. IDE permeability across MDCKII-MDR1 cell monolayers from the SLN under investigation was 0.40-0.53 fold lower than free IDE and no significant difference was observed comparing IDE permeation from all the SLN tested. It is noteworthy that IDE loading into SLN avoided the use of an organic solvent to solubilize IDE, a poor water soluble compound, allowing the parenteral administration of this drug in aqueous vehicles. Furthermore, the results of in vitro transport studies, performed using fluorescein-dextran 4000 (FD4) and diazepam (DZ) as markers of the paracellular pathway and the transcellular pathway, respectively, pointed out that IDE could permeate via a transcellular pathway. Therefore, these novel nanocarriers could be regarded as a promising strategy to design delivery systems for IDE administration to the brain, deserving further investigations under in vivo conditions.     

Fabrication of solid lipid nanoparticles of lurasidone HCl for oral delivery: optimization,in vitro characterization,cell line studies and in vivo efficacy in schizophrenia

Objective: The aim of the present investigation was to investigate the efficacy of solid lipid nanoparticles (SLNs) to enhance the absorption and bioavailability of lurasidone hydrochloride (LH) following oral administration.

Methods: The LH loaded SLNs (LH-SLNs) were prepared by high pressure homogenization (HPH) method, optimized using box Behnken design and evaluated for particle size (PS), entrapment efficiency (EE), morphology, FTIR, DSC, XRD, in vitro release, ex vivo permeation, transport studies across Caco-2 cell line and in vivo pharmacokinetic and pharmacodynamic studies.

Results: The LH-SLNs had PS of 139.8?±?5.5?nm, EE of 79.10?±?2.50% and zeta potential of ?30.8?±?3.5?mV. TEM images showed that LH-SLNs had a uniform size distribution and spherical shape. The in vitro release from LH-SLNs followed the Higuchi model. The ex vivo permeability study demonstrated enhanced drug permeation from LH-SLNs (>90%) through rat intestine as compared to LH-suspension. The SLNs were found to be taken up by energy dependent, endocytic mechanism which was mediated by clathrin/caveolae-mediated endocytosis across Caco-2 cell line. The pharmacokinetic results showed that oral bioavailability of LH was improved over 5.16-fold after incorporation into SLNs as compared to LH-suspension. The pharmacodynamic study proved the antipsychotic potential of LH-SLNs in the treatment of schizophrenia.

Conclusion: It was concluded that oral administration of LH-SLNs in rats improved the bioavailability of LH via lymphatic uptake along with improved therapeutic effect in MK-801 induced schizophrenia model in rats.     

In vitro and in vivo toxicity of CdTe nanoparticles

Cadmium telluride (CdTe) nanoparticles exhibit strong and stable fluorescence that is attractive for many applications such as biological probing and solid state lighting. The evaluation of nanoparticle toxicity is important for realizing these practical applications. However, no systematic studies of CdTe nanoparticle toxicity have been reported. We investigated and compared the size- and concentration-dependent cytotoxicity of CdTe nanoparticles in human hepatoma HepG2 cells using the MTT assay. CdTe nanoparticles elicited cytotoxicity in a concentration- and size-dependent manner, with smaller-sized particles exhibiting somewhat higher potency. Lesser cytotoxicity of partially purified CdTe-Red particles (following methanol precipitation and resuspension) suggested that free cadmium ions may contribute to cytotoxicity. We also evaluated the acute toxicity of CdTe-Red particles following intravenous exposure in male rats (2 micromol/kg). Few signs of functional toxicity or clinical (urinary or blood) changes were noted. Interestingly, motor activity was transiently reduced (2 hours after treatment) and then significantly increased at a later timepoint (24 hours after dosing). These studies provide a framework for further characterizing the in vitro and in vivo toxic potential of different types of CdTe nanoparticles and suggest that the nervous system may be targeted by these nanoparticles under some conditions.     

Preparation and pharmacokinetic evaluation of Tashinone IIA solid lipid nanoparticles

Tashinone IIA loaded solid lipid nanoparticles (TA-SLN) coated with poloxamer 188 was prepared by emulsification/evaporation. The TA-SLN was characterized by transmission electron microscope and dynamic light scattering (DLS). The results showed that the TA-SLN had an average diameter of 98.7 nm with a zeta potential of - 31.6 mv and the drug loading of 4.6% and entrapment efficiency of 87.7%. In vitro release experiment showed that the release of Tashinone IIA from TA-SLN was in accordance with the Weibull equation. The best model fitting experimental data was a two-compartment open model with first-order. The area under curve of plasma concentration-time (AUC) and mean residence time (MRT) of TA-SLN were much higher than those of Tashinone IIA control solution (TA-SOL). The results of pharmacokinetic studies in rabbits indicated that the formulation of TA-SLN was successful in providing a delivery of slow release of Tashinone IIA.     

Pharmacokinetic and pharmacodynamic studies of nisoldipine-loaded solid lipid nanoparticles developed by central composite design

Abstract

Objective: Nisoldipine (ND) is a potential antihypertensive drug with low oral bioavailability. The aim was to develop an optimal formulation of ND-loaded solid lipid nanoparticles (ND-SLNs) for improved oral bioavailability and pharmacodynamic effect by using a two-factor, three-level central composite design. Glyceryl trimyristate (Dynasan 114) and egg lecithin were selected as independent variables. Particle size (Y₁), PDI (Y₂) and entrapment efficiency (EE) (Y₃) of SLNs were selected as dependent response variables.

Methods: The ND-SLNs were prepared by hot homogenization followed by ultrasonication. The size, PDI, zeta potential, EE, assay, in vitro release and morphology of ND-SLNs were characterized. Further, the pharmacokinetic (PK) and pharmacodynamic behavior of ND-SLNs was evaluated in male Wistar rats.

Results: The optimal ND-SLN formulation had particle size of 104.4?±?2.13?nm, PDI of 0.241?±?0.02 and EE of 89.84?±?0.52%. The differential scanning calorimetry and X-ray diffraction analyses indicated that the drug incorporated into ND-SLNs was in amorphous form. The morphology of ND-SLNs was found to be nearly spherical by scanning electron microscopy. The optimized formulation was stable at refrigerated and room temperature for 3 months. PK studies showed that 2.17-fold increase in oral bioavailability when compared with a drug suspension. In pharmacodynamic studies, a significant reduction in the systolic blood pressure was observed, which sustained for a period of 36?h when compared with a controlled suspension.

Conclusion: Taken together, the results conclusively demonstrated that the developed optimal ND-SLNs caused significant enhancement in oral bioavailability along with pharmacodynamic effect.     

Lonidamine solid dispersions: in vitro and in vivo evaluation

Solid dispersions of lonidamine in PEG 4000 and PVP K 29/32 were prepared by the spray-drying method. Then, the binary systems were studied and characterized using differential scanning calorimetry, hot stage microscopy, and x-ray diffractometry. In vitro dissolution studies of the solid dispersed powders were performed to verify if any lonidamine dissolution rate or water solubility improvement occurred. In vivo tests were carried out on the solid dispersions and on the cyclodextrin inclusion complexes to verify if this lonidamine water solubility increase was really able to improve the in vivo drug plasma levels. Drug water solubility was increased by the solid dispersion formation, and the extent of increase depended on the polymer content of the powder. The greater increase of solubility corresponded to the highest content of polymer. Both the solid dispersions and the cyclodextrin complexes were able to improve the in vivo bioavailability of the lonidamine when administered per os. Particularly, the AUC of the drug plasma levels was increased from 1.5 to 1.9-fold depending on the type of carrier.     

Characterization and formulation optimization of solid lipid nanoparticles in vitamin K1 delivery

Background: Solid lipid nanoparticle (SLN) systems have been applied to various drugs and delivery routes. Vitamin K1 is an important cofactor for maintaining hemostasis and preventing hemorrhage. Method: Vitamin K1-loaded SLNs are systematically being developed by optimizing triglycerides and lipophilic and hydrophilic surfactants based on the size and stability of the resulting SLNs. Concentrations of the surfactants, Myverol and Pluronic, were optimized by a central composite design and response surface methodology. Vitamin K1 (phylloquinone) was used as a lipophilic drug in the SLN system to evaluate the potential for oral delivery. Results: Vitamin K1-loaded SLNs had a mean size of 125 nm and a zeta potential of ?23 mV as measured by photon correlation spectroscopy. The prepared SLNs were examined by differential scanning calorimetry and transmission electron microscopy and found to have an imperfect crystalline lattice and a spherical morphology. Effects of ultrasonication duration and drug load on the particle size and entrapment efficiency of the SLNs were also evaluated. Conclusion: More than 85% of the vitamin K1 was entrapped in SLNs when the payload was <5%. The vitamin K1 in SLNs was stable for a 54-h duration in simulated gastric and intestinal fluids. The particle size and vitamin K1 entrapped in the SLN were stable after 4 months of storage at 25°C. The results demonstrated that SLNs prepared herein can potentially be exploited as carriers for the oral delivery of vitamin K1.     

Histopathological evaluation of caffeine-loaded solid lipid nanoparticles in efficient treatment of cellulite

Context: Cellulite refers to dimpled appearance of the skin, usually located in the thighs and buttocks regions of most adult women.

Objective: The aim of this study was to formulate topically used caffeine-loaded solid lipid nanoparticle (SLN) for the treatment of cellulite.

Methods: SLNs were prepared by hot homogenization technique using Precirol® as lipid phase. The physical characterization and stability studies of SLNs as well as in vitro skin permeation and histological studies in rat skin were conducted.

Results: The mean particle size, encapsulation efficiency and loading efficiency percentages for optimized SLN formulation were 94?nm, 86 and 28%, respectively. In vitro drug release demonstrated that caffeine-loaded SLN incorporated into carbopol made hydrogel (caffeine-SLN-hydrogel) exhibited a sustained drug release compared to the caffeine hydrogel over 24?h. Caffeine-loaded SLNs showed a good stability during 12 months of storage at room temperature. The DSC and XRD results showed that caffeine was dispersed in SLN in an amorphous state. In vitro permeation studies illustrated higher drug accumulation in the skin with caffeine-SLN-hydrogel compared to caffeine hydrogel. The flux value of caffeine through rat skin in caffeine-SLN-hydrogel was 3.3 times less than caffeine hydrogel, representing lower systemic absorption. In contrast with caffeine hydrogel, the histological studies showed the complete lysis of adipocytes by administration of caffeine-SLN-hydrogel in the deeper skin layers.

Conclusion: Results of this study indicated that SLNs are promising carrier for improvement of caffeine efficiency in the treatment of cellulite following topical application on the skin.     

Characterization and body distribution of beta-elemene solid lipid nanoparticles (SLN)

Solid lipid nanoparticles (SLN) containing β-elemene, a volatile oil used for the treatment of cancer, were prepared by the method combining probe sonication and membrane extrusion. Effects of the formulations and procedures on the characteristics of SLN were investigated. Body distribution of β-elemene SLN in rats after intravenous administration was compared with that of the commercial emulsion. The results showed that dispersing the surfactant in the melted lipid matrix could obtain smaller particles than that dispersing in the water phase. Increasing the ratio of monostearin in the lipid matrix or the concentration of surfactant reduced the mean volume size of the SLN. Optimized formulation was composed of monostearin and precirol ATO 5 at a mass ratio of 3:7, which was quite stable for 8 months at room temperature. In vitro release of β-elemene from the SLN was slow and stable without obvious burst release and was found to follow the Higuich equation. After intravenous administration, the β-elemene levels after 5 min injection of SLN formulation were 1.5, 2.9, and 1.4 times higher than those of β-elemene emulsion in liver, spleen, and kidney, respectively, while the concentrations of β-elemene were decreased 30% in heart and lung. Therefore, the SLN containing β-elemene might be an attractive candidate for the treatment of liver cancer.