[Combination of shikonin and gefitinib reverses drug resistance in human non-small cell lung cancer and its mechanism].

The occurrence and development of tumors are associated with the cell energy metabolism. Inhibiting energy metabolism of lung cancer cells is an important strategy to overcome drug resistance. Based on the cellular energy metabolism pathway, this study observed the effect of combination of shikonin(SKN) and gefitinib(GFB) on the drug resistance in non-small cell lung cancer and explored the underlying mechanism. The human non-small cell lung cancer line HCC827/GR resistant to gefitinib was used as the cell model in vitro. The CCK-8 assay and flow cytometry were employed to investigate the cell viability and apoptosis, respectively. The high performance liquid chromatography was employed to measure the intracellular accumulation of GFB. A Seahorse XFe96 Analyzer was used to detect the changes of cellular energy metabolism. Western blot was employed to determine the expression of the proteins involved in the drug resistance. The tumor-bearing nude mouse model was used to verify the efficacy of SKN+GFB in overcoming drug resistance in vivo. The results showed that SKN+GFB significantly reduced the IC_(50) of GFB on HCC827/GR cells, with the combination index of 0.628, indicating that the combination of the two drugs had a synergistic effect and promoted cell apoptosis. SKN increased the intracellular accumulation of GFB. SKN+GFB lowered the oxygen consumption rate(OCR) and glycolytic proton efflux rate(GlycoPER) in cell energy metabolism, and down-regulated the overexpression of PKM2, p-EGFR, P-gp, and HIF-1α in drug resistance. The results of reversing drug resistance test in vivo showed that GFB or SKN alone had no significant antitumor effect, while the combination at different doses induced the apoptosis of the tumor tissue and inhibited the expression of PKM2 and P-gp, demonstrating a significant antitumor effect. Moreover, the tumor inhibition rate in the high-dose combination group reached 64.01%. In summary, SKN+GFB may interfere with the energy metabolism to limit the function of HCC827/GR cells, thus reversing the GFB resistance in non-small cell lung cancer.

[Effect and mechanism of Xihuang Pills on rats with precancerous lesions of breast].

The purpose of this study was to explore the effect and mechanism of Xihuang Pills on rats with precancerous lesions of the breast. Of 48 healthy female rats, 8 were randomly selected as blank group, and the other 40 were treated with 7,12-dimethylbenzanthracene(DMBA) combined with estrogen and progestin to establish a model of precancerous lesions of the breast. The successfully modeled rats were randomly divided into a model group, a tamoxifen group(1.8 mg·kg~(-1)·d~(-1)), a Xihuang Pills low-dose group(0.3 g·kg~(-1)·d~(-1)), a medium-dose group(0.6 g·kg~(-1)·d~(-1)) and a high-dose group(1.2 g·kg~(-1)·d~(-1)). After 30 days of admi-nistration, the histopathological changes of viscera and breast were observed by haematoxylin and eosin(HE) staining, and the visceral index was calculated. Enzyme linked immunosorbent assay(ELISA) was used to detect the contents of estradiol(E_2) and progesterone(P) in serum. The protein expressions of vascular endothelial growth factor(VEGF) and fibroblast growth factor 2(FGF2) were detected by immunohistochemistry. The protein expressions of VEGF, vascular endothelial growth factor receptor 2(VEGFR2), phosphorylated-vascular endothelial growth factor receptor 2(p-VEGFR2), B-cell lymphoma-2(Bcl-2), and Bcl-2 associated X protein(Bax) were detected by Western blot and the mRNA expressions of VEGF, FGF2, CXC-chemokine receptor 4(CXCR4), cysteine aspartic acid-specific protease(caspase-3), and stromal cell-derived factor 1(SDF-1) were detected by real-time polymerase chain reaction(RT-PCR). HE staining revealed that the model group had some liver and kidney damages and severe hyperplastic mammary tissue, while the Xihuang Pills high-dose group had mild hyperplasia. Compared with the model group, the Xihuang Pills groups had lo-wer ovarian coefficient(P<0.05 or P<0.01) and Xihuang Pills high-dose group had lower uterine coefficient(P<0.01). ELISA results showed that compared with the model group, expressions of E_2 and P in Xihuang Pills high-dose group were significantly decreased(P<0.05 or P<0.01). Immunohistochemistry, Western blot and RT-PCR indicated that compared with the conditions in the model group, the protein and mRNA expressions of VEGF and FGF2 in the Xihuang Pills groups were down-regulated(P<0.05 or P<0.01), and the protein expression of Bcl-2 was lowered(P<0.01); there was a decrease in the protein expressions of VEGFR2 and p-VEGFR2(P<0.01), a down-regulation in the mRNA expressions of CXCR4 and SDF-1(P<0.01), while an increase in the mRNA expression of caspase-3(P<0.01) in both Xihuang Pills medium-dose and high-dose groups; the protein expression of Bax in Xihuang Pills high-dose group was increased(P<0.01). The above results indicated that Xihuang Pills can effectively intervene in precance-rous lesions of the breast, and the mechanism may be related to the regulation of E_2 and P secretion as well as the inhibition of angiogenesis and chemokine receptor expression, thus controlling the occurrence of precancerous lesions of the breast in rats.

[Effects of Platycodonis Radix-Curcumae Rhizoma on oral nanoparticle uptake and in vitro inhibition against breast cancer metastasis].

This study combined the herbal pair Platycodonis Radix-Curcumae Rhizoma(PR-CR) possessing an inhibitory effect on tumor cell proliferation and metastasis with the active component of traditional Chinese medicine(TCM) silibinin-loaded nanoparticles(NPs) with a regulatory effect on tumor microenvironment based on the joint effect on tumor cells and tumor microenvironment to inhi-bit cell metastasis. The effects of PR-CR on the cellular uptake of NPs and in vitro inhibition against breast cancer proliferation and metastasis were investigated to provide an experimental basis for improving nanoparticle absorption and enhancing therapeutic effects. Silibinin-loaded lipid-polymer nanoparticles(LPNs) were prepared by the nanoprecipitation method and characterized by transmission electron microscopy. The NPs were spherical or quasi-spherical in shape with obvious core-shell structure. The mean particle size was 107.4 nm, Zeta potential was-27.53 mV. The cellular uptake assay was performed by in vitro Caco-2/E12 coculture cell model and confocal laser scanning microscopy(CLSM), and the results indicated that PR-CR could promote the uptake of NPs. Further, in situ intestinal absorption assay by the CLSM vertical scanning approach showed that PR-CR could promote the absorption of NPs in the enterocytes of mice. The inhibitory effect of NPs on the proliferation and migration of 4T1 cells was analyzed using 4T1 breast cancer cells and co-cultured 4T1/WML2 cells, respectively. The results of the CCK8 assay showed that PR-CR-containing NPs could enhance the inhibition against the proliferation of 4T1 breast cancer cells. The wound healing assay indicated that PR-CR-containing NPs enhanced the inhibition against the migration of 4T1 breast cancer cells. This study enriches the research on oral absorption of TCM NPs and also provides a new idea for utilizing the advantages of TCM to inhibit breast cancer metastasis.

[Comparison of in vivo plasma pharmacokinetics and urine excretion of main components in Xihuang Formula in rats with precancerous lesions of breast cancer].

The UPLC-MS/MS was established for the determination of acetyl-11-keto-beta-boswellic acid(AKBA) and ß-boswellic acid(ß-BA), the main active components of Olibanum and Myrrha extracts in Xihuang Formula, in rat plasma and urine. The effects of compatibility on the pharmacokinetic behaviors of AKBA and ß-BA in rats were investigated, and the differences in pharmacokinetic behaviors between healthy rats and rats with precancerous lesions of breast cancer were compared. The results showed that compared with RM-NH and RM-SH groups, the AUC_(0-t) and AUC_(0-∞) of ß-BA increased(P<0.05 or P<0.01), T_(max) decreased(P<0.05 or P<0.01), and C_(max) increased(P<0.01) after compatibility. The trends of AKBA and ß-BA were the same. Compared with RM-SH group, the T_(max) decreased(P<0.05), C_(max) increased(P<0.01), and the absorption rate increased in the normal group of Xihuang Formula. The results of urinary excretion showed that there was a decreasing trend in the urinary excretion rate and total urinary excretion of ß-BA and AKBA after compatibility, but there was no statistical difference. Compared with normal group of Xihuang Formula, the AUC_(0-t) and AUC_(0-∞) of ß-BA increased(P<0.05), T_(max) increased(P<0.05), and the clearance rate decreased in the breast precancerous lesion group. AUC_(0-t) and AUC_(0-∞) of AKBA showed an increasing trend, the in vivo retention time was prolonged, and the clearance rate was reduced, but there was no significant difference compared with the normal group. The cumulative urinary excretion and urinary excretion rate of ß-BA and AKBA decreased under pathological conditions, indicating that pathological conditions could affect the in vivo process of ß-BA and AKBA, and reduce their excretion in the form of prototype drugs, showing different pharmacokine-tic characteristics from normal physiological conditions. In this study, UPLC-MS/MS analysis method was established, which was sui-table for in vivo pharmacokinetic analysis of ß-BA and AKBA. This study laid a foundation for the development of new dosage forms of Xihuang Formula.

[Effects of shell composition in shell-core structured nanoparticles on oral physiological barrier and bioavailability].

The present study prepared shell-core nanoparticles comprising poly(lactic-co-glycolic acid)(PLGA) cores encapsulated by shells composed of mixed lipids(Lipoid S100 and DSPE-PEG 2000) or polymer F127 to investigate the effects of shell composition on overcoming physiological barriers of gastrointestinal mucus and intestinal epithelial cells and improving bioavailability.The results are expected to provide references for the research on the improvement of the oral bioavailability of Chinese medicine by nanocar-riers. Silibinin(SLB) was used as a model drug to prepare PLGA nanoparticles coated with the shell of mixed lipids(SLB-LPNs) or F127(SLB-FPNs) via a modified nanoprecipitation method.Transmission electron microscopy showed that both LPNs and FPNs were spherical with a core-shell structure.The average particle sizes of SLB-LPNs and SLB-FPNs were(94.13±2.23) and(95.42±4.91) nm, respectively.The Zeta potential values were(-39.3±2.8) and(-17.0±0.2) mV, respectively.X-ray diffraction analysis revealed the presence of SLB in the two types of nanoparticles in a molecular or amorphous state.The ability of nanoparticles to cross both the mucus and epithelial barriers were evaluated using the cellular internalization kinetics assay.LPNs showed a higher rate of cell internalization than FPNs, indicating that LPNs could penetrate the mucus layer and become internalized by cells more rapidly.As revealed by the in vivo pharmacokinetic assay in rats with SLB suspension as the reference, the relative oral bioavailability of SLB-LPNs and SLB-FPNs was 400.37% and 923.31%, respectively.The effect of SLB-FPNs in improving oral bioavailability was more significant than that of SLB-LPNs.In summary, shell composition can influence the ability of nanoparticles to overcome oral physiological bar-riers, such as the mucus layer and intestinal epithelial cells, and improve oral bioavailability.Shell-core structured nanoparticles are promising nanocarriers for oral drug delivery systems.

[Improvement in compatibility of hot melt pressure-sensitive adhesive with cinnamon volatile oil and in vitro transdermal property by physical blending].

Hot melt pressure-sensitive adhesive(HMPSA) has broad application potential in the field of traditional Chinese medicine(TCM) plasters due to its high drug loading, weak skin irritation, satisfactory adhesion, etc. compared with rubber plasters.However, the structure of HMPSA is prone to suffer from the damage caused by volatile oils in TCM plasters. In view of this, a kind of HMPSA with a stable structure was prepared by physical blending of DINCH, polypropylene wax and liquid rubber(LIR) in the present study, which is denoted as DPL. The dosage of cinnamon volatile oil(CVO), the model drug, was selected with viscosity, softening point and cohesion as evaluation indexes. The interaction between DPL and HMPSA was investigated by Fourier transform infrared spectroscopy(FT-IR) and differential scanning calorimetry(DSC). The compatibility of HMPSA with CVO and its transdermal ability were studied by in vitro transdermal test, adhesion, scanning electron microscopy( SEM) and rheological evaluation. The results showed that 5% CVO began to damage the structure of HMPSA. The initial adhesion and holding adhesion of DPL-modified HMPSA(DPL-HMPSA) were not significantly changed compared with those of HMPSA, whereas the 180° peel strength was decreased. FI-IR unraveled that DPL formed the n-π conjugated system with styrene-isoprene-styrene block copolymer(SIS), and there was no significant difference in the glass transition temperature according to DSC results, which indicated the good compatibility of DPL with HMPSA. With 5% CVO loaded, the drug content of DPL-HMPSA was 1. 14 times higher than that of HMPSA, and the decrease rate of drug content in DPL-HMPSA was 16% lower than that in HMPSA after 3 months. SEM demonstrated that CVO did not cause obvious structural damage to DPL-HMPSA. Rheological evaluation revealed that the storage modulus and loss factor of DPL-HMPSA were higher than those of HMPSA, and the cohesion was also stronger. The percutaneous penetration rate of cinnamaldehyde in DPL-HMPSA was 2. 25 times that of HMPSA. In conclusion, DPL-HMPSA had more stable structure, better compatibility with CVO, and higher in vitro transdermal efficiency of cinnamaldehyde than before the modification. This study can provide reference for the mitigation of the matrix structure damage caused by volatile oil components in TCM plasters and the enhancement of the content and in vitro transdermal rate of drug.

[Study on effect of SuperTab 40LL on compression characteristics of musk sustained-release mini-tablets based on mathematical models].

In this paper, co-processed lactose SuperTab 40 LL was selected as fillers to study the preparation of musk sustained-release mini-tablets in the Xihuang multiple-unit drug release system. Musk sustained-release tablets containing different proportions of SuperTab 40 LL and MCC were prepared under various pressures, and then the compressibility and compactibility of these prescriptions were evaluated by Walker, Heckel and Ryshkewitch-Duckworth equations. In addition, the fluidity of the prescriptions was evaluated by parameters of Kawakita equation. There was a comprehensive analysis of the effect of SuperTab 40 LL on musk sustained-release mini-tablets combined with the appearance of SuperTab 40 LL and their tensile strength. The results shown that SuperTab 40 LL had better compression process through the Heckel equation, and the direct compression process of drug powders with excipients can be analyzed by the Kawakita and Ryshkewitch-Duckworth equations. As a new type of co-processed lactose, SuperTab 40 LL had a good fluidity and compactibility. SuperTab 40 LL may undergo particle crushing and plastic deformation during the compression process, which increased the contact area and bonding sites between the particles, and aggregated and shaped the mixed powder easy. Moreover, MCC showed a synergistic effect, and the combined application with SuperTab 40 ll could effectively improve the fluidity and compressibility of the musk sustained-release powder. When the ratio of SuperTab 40 LL and MCC was 2∶1, musk sustained-release mini-tablets had a high drug loading capacity and good compactibility in line with the design objectives.

Improved Biosafety and Transdermal Delivery of Aconitine via Diethylene Glycol Monoethyl Ether-Mediated Microemulsion Assisted with Microneedles.

In the current study, diethylene glycol monoethyl ether-mediated microemulsions were combined with microneedles for enhanced transdermal aconitine delivery. The oil-in-water microemulsion increasedaconitine solubility and enhanced transdermal drug delivery and assistance with metal microneedles enhanced permeation of the aconitine-loaded microemulsion. Carried by the microemulsion, the in vitro permeability of aconitine was significantly enhanced, and further improved using microneedles. In vivo microdialysis revealed that the subcutaneous local drug concentration reached a high level within 30 min and remained relatively consistent to the end of the experimental period. AUC0-t of the microemulsion group was significantly higher than that of the aqueous solution group, and the microemulsion combined with microneedles group achieved the highest AUC0-t among the tested groups. The microemulsion and microdialysis probe also showed good biocompatibility with skin tissue. The microemulsion could be internalized by HaCaT and CCC-ESF-1 cells via lysosomes. The in vitro cytotoxicity of aconitine toward skin cells was reduced via encapsulation by microemulsion, and the prepared microemulsion developed no skin irritation. Hence, transdermal aconitine delivery and drug biosafety were effectively improved by loading into the microemulsion and assisting with microneedles, and in vivo microdialysis technique is suitable for realtime monitoring of transdermal drug delivery with microemulsion-based drug vehicles.

Exploring the Potential of Mesoporous Silica as a Carrier for Puerarin: Characterization, Physical Stability, and In Vivo Pharmacokinetics.

The aim of this study was to evaluate the use of a novel porous silica carrier, AEROPERL® 300 Pharma (AP), to improve the in vitro release and oral bioavailability of puerarin (PUE) in solid dispersions (SDs). PUE-AP SD formulations with different ratios of drug to silica (RDS) were prepared by the solvent method. The scanning electron microscopy (SEM) results indicated that the dispersion of PUE improved as the concentration of AP was increased. The differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results revealed that PUE mostly existed in an amorphous state in the SDs. The rate of drug dissolution from the SDs was significantly higher than that from the PUE powder (p < 0.05). The in vitro drug release percentage from the PUE-AP SDs increased as the RDS was reduced. The oral bioavailability of PUE from the SDs improved when using AP, as indicated by AUC(0-∞), which was 2.05 and 2.01 times greater than that of the PUE (API) and PVP K30 SDs, respectively (p < 0.05). The drug content, in vitro release profiles, and the amorphous state of PUE in the PUE-AP SDs showed no significant changes after being stored at room temperature for 6 months or under accelerated conditions (40 ± 2°C, 75 ± 5% relative humidity) for 3 months. AP has a high pore volume, large specific surface area, excellent flowability, and hydrophilic properties, making it capable of improving the dissolution and bioavailability of poorly water-soluble drugs.

A novel microemulsion-based isotonic perfusate modulated by Ringer's solution for improved microdialysis recovery of liposoluble substances.

BACKGROUND: Microdialysis is promising technique for dynamic microbiochemical sampling from tissues. However, the application of typical aqueous perfusates to liposoluble substances is limited. In this study, a novel microemulsion (ME)-based isotonic perfusate (RS-ME) was prepared to improve the recovery of liposoluble components using microdialysis probes. RESULTS: Based on pseudo-ternary phase diagrams and comparisons of the ME area, Kolliphor® EL and Transcutol® P were selected as the surfactant and co-surfactant, respectively, with a weight ratio (Km) of 2:1 and ethyl oleate as the oil phase. The ME was mixed with Ringer's solution at a 1:6 ratio (v/v) to obtain the isotonic RS-ME. The droplet size distribution of the ME in RS-ME was 78.3 ± 9.2 nm, with a zeta potential of - 3.5 ± 0.3 mV. By microdialysis perfusion, RS-ME achieved higher recovery rates of the poorly water-soluble compounds evodiamine (EVO) and ruthenium (RUT), i.e., 58.36 ± 0.57% and 49.40 ± 0.57%, respectively, than those of 20% (v/v) PEG 400 Ringer's solution (RS-PEG) and 10% (v/v) ethanol Ringer's solution (RS-EtOH). In vivo microdialysis experiments confirmed that RS-ME captured EVO and RUT molecules around the dialysis membrane more efficiently and exhibited less spreading than RS-PEG and RS-EtOH. CONCLUSIONS: Owing to the nanosized droplets formed by lipid components in the RS-ME and the limited dispersion out of the dialysis membrane, we obtained good biocompatibility and reliable dialysis results, without affecting the tissue microenvironment. As a novel perfusate, RS-ME provides an easy and reliable approach to the microdialysis sampling of fat-soluble components.

DOC-LS, a new liposome for dermal delivery, and its endocytosis by HaCaT and CCC-ESF-1 cells.

The main objective of this work was to investigate the uptake channels of skin cells through which coumarin 6, transported by deoxycholate-mediated liposomes (DOC-LS), was internalised; this was also compared against the action of conventional LS. Coumarin 6-loaded DOC-LS and LS were characterised for size distribution, zeta potential, and shape, and analysed in vitro in human epidermal immortal keratinocyte (HaCaT) (epidermal) and human embryonic skin fibroblast (CCC-ESF-1) (dermal) cell lines. Various endocytosis inhibitors were incubated with cells treated with the nanocarriers. Flow cytometry results indicated that HaCaT and CCC-ESF-1 cells internalise the tested preparations through pinocytotic vesicles, macropinocytosis, clathrin-mediated endocytic pathways, and via lysosomes, which consume a considerable amount of energy. The endocytosis pathways of DOC-LS and LS showed no difference. This study provides a basis for the application of LS being combined with a microneedle system for efficient intracellular drug delivery, targeting cutaneous histocyte disorders.

[Research progress on Chinese medicines with topical administration in umbilical region].

Based on the Chinese medicines with topical administration in umbilical region approved by China Food and Drug Administration (CFDA), this paper would comb and analyze their dosage forms, varieties and clinical applications. On the other hand, through consulting literature materials, the research progress was reviewed and the main challenges faced by the medicines were discussed in detail as well. This paper elaborates that the preparations with topical administration in umbilical region, as an important branch in Chinese medicine external therapy, have unique advantages. However, there are still some problems such as rough workmanship, lacking internationally accepted quality control standards, scarcity of pharmacological and clinical evidences and biopharmaceutical researches. Meanwhile, proper measures and suggestions are put forward.

Enhanced immunization via dissolving microneedle array-based delivery system incorporating subunit vaccine and saponin adjuvant.

PURPOSE: To enhance the immunogenicity of the model subunit vaccine, ovalbumin (OVA) was combined with platycodin (PD), a saponin adjuvant. To reduce the toxicity of PD, OVA, and adjuvant were loaded together into liposomes before being incorporated into a dissolving microneedle array. METHODS: OVA- and PD-loaded liposomes (OVA-PD-Lipos) were prepared using the film dispersion method. Their uptake behavior, toxicity to mouse bone marrow dendritic cells (BMDCs), and hemolytic activity to rabbit red blood cells (RBCs) were evaluated. The OVA-PD-Lipos were incorporated into a dissolving microneedle array. The chemical stability of OVA and the physical stability of OVA-PD-Lipos in microneedle arrays were investigated. The immune response of Institute of Cancer Research mice and potential skin irritation reaction of rabbits to OVA-PD-Lipos-MNs were evaluated. RESULTS: The uptake of OVA by mouse BMDCs was greatly enhanced when OVA was prepared as OVA-PD-Lipos, and in this form, the toxicity of PD was dramatically reduced. OVA was chemically stable as OVA-PD-Lipos, when OVA-PD-Lipos was incorporated into a dissolving microneedle array. Institute of Cancer Research mice treated with OVA-PD-Lipos-MNs showed a significantly enhanced immune response. PD combined with OVA elicited a balanced Th1 and Th2 humoral immune response in mice, with minimal irritation in rabbit skin. CONCLUSION: The dissolving microneedle array-based system is a promising delivery vehicle for subunit vaccine and its adjuvant.

Co-delivery of evodiamine and rutaecarpine in a microemulsion-based hyaluronic acid hydrogel for enhanced analgesic effects on mouse pain models.

The aim of this study was to improve the analgesic effect of evodiamine and rutaecarpine, using a microemulsion-based hydrogel (ME-Gel) as the transdermal co-delivery vehicle, and to assess hyaluronic acid as a hydrogel matrix for microemulsion entrapment. A microemulsion was formulated with ethyl oleate as the oil core to improve the solubility of the alkaloids and was loaded into a hyaluronic acid-structured hydrogel. Permeation-enhancing effects of the microemulsion enabled evodiamine and rutaecarpine in ME-Gel to achieve 2.60- and 2.59-fold higher transdermal fluxes compared with hydrogel control (p<0.01). The hyaluronic acid hydrogel-containing microemulsion exhibited good skin biocompatibility, whereas effective ME-Gel co-delivery of evodiamine and rutaecarpine through the skin enhanced the analgesic effect in mouse pain models compared with hydrogel. Notably, evodiamine and rutaecarpine administered using ME-Gel effectively down-regulated serum levels of prostaglandin E2, interleukin 6, and tumor necrosis factor α in formaldehyde-induced mouse pain models, possibly reflecting the improved transdermal permeability of ME-Gel co-delivered evodiamine and rutaecarpine, particularly with hyaluronic acid as the hydrogel matrix.

Solid Lipid Nanoparticles Formulated for Transdermal Aconitine Administration and Evaluated In Vitro and In Vivo.

In this study, solid lipid nanoparticles were formulated for transdermal delivery of aconitine to improve its safety and permeability. Aconitine-loaded solid lipid nanoparticles were formulated as an oil-in-water microemulsion. Drug encapsulation efficiencies for these formulations were higher than 85%, and correlated positively with levels of surfactant and oil matrix. The size of the solid lipid nanoparticles was increased with an increase of the oil matrix, and reduction of the surfactant levels. Compared with an ethanol tincture, all the tested solid lipid nanoparticle formulations achieved improved transdermal fluxes and drug deposition in skin in vitro. Real-time monitoring of drug distribution in rat dermis using in vivo microdialysis showed that aconitine concentration was markedly higher following application of solid lipid nanoparticles, compared to tincture, throughout the experimental period. A regional comparison of rat skin found that application of solid lipid nanoparticles to the scapular region resulted in higher AUC(0-t) and C(max), compared to those achieved with application to the abdomen or chest (p < 0.05). In contrast, the application to the chest resulted in the lowest AUC(0-t) and C(max). Together with findings of a structural study of the skin, these results indicated that the drug accumulated more readily in thicker skin regions, and to a lesser extent in well-perfused skin, because of drug transfer to capillaries. The superior transdermal permeability of aconitine-loaded solid lipid nanoparticles contributed to stronger anti-inflammatory and analgesic effects on mouse in vivo models of pain than the tincture (p < 0.05). In vitro and in vivo studies indicated that smaller particle sizes of solid lipid nanoparticles enhanced the transdermal permeability of aconitine, which can promote drug efficacy, reduce administration time, and improve medication safety.

An in vitro and in vivo comparison of solid and liquid-oil cores in transdermal aconitine nanocarriers.

This study compared transdermal aconitine delivery using solid lipid nanoparticles (SLN) and microemulsion (ME) vehicles. Aconitine-loaded SLN and ME were formulated with the same surfactant, cosurfactant, and water content, with an equal amount of oil matrix (ATO 888 for SLN and ethyl oleate for ME). These nanosized formulations (70-90 nm) showed suitable pH values and satisfactory skin tissue biocompatibility. SLN contained a higher concentration of smaller nanoparticles, compared with that in ME. Neither of the nanocarriers penetrated across excised skin in their intact form. In vitro transdermal delivery studies found that transdermal aconitine flux was lower from SLN than from ME (p < 0.05), but skin aconitine deposition was higher using SLN (p < 0.05). Fluorescence-activated cell sorting indicated that in vitro uptake of fluorescently labeled SLN by human immortalized keratinocyte (HaCaT) cells was greater than that of ME, indicating that a transcellular pathway may contribute to cutaneous drug absorption more effectively from SLN. In vivo studies found that these formulations could loosen stratum corneum layers and increase skin surface crannies, which may also enhance transdermal aconitine delivery. SLN produced a more sustained aconitine release, indicating that compared with ME, this transdermal delivery vehicle may reduce the toxicity of this drug.

Preparation and evaluation of microemulsion-based transdermal delivery of total flavone of rhizoma arisaematis.

The aims of the present study were to investigate the skin permeation and cellular uptake of a microemulsion (ME) containing total flavone of rhizoma arisaematis (TFRA), and to evaluate its effects on skin structure. Pseudo-ternary phase diagrams were constructed to evaluate ME regions with various surfactants and cosurfactants. Eight formulations of oil-in-water MEs were selected as vehicles, and in vitro skin-permeation experiments were performed to optimize the ME formulation and to evaluate its permeability, in comparison to that of an aqueous suspension. Laser scanning confocal microscopy and fluorescent-activated cell sorting were used to explore the cellular uptake of rhodamine 110-labeled ME in human epidermal keratinocytes (HaCaT) and human embryonic skin fibroblasts (CCC-ESF-1). The structure of stratum corneum treated with ME was observed using a scanning electron microscope. Furthermore, skin irritation was tested to evaluate the safety of ME. ME formulated with 4% ethyl oleate (weight/weight), 18% Cremophor EL (weight/weight), and 18% Transcutol P, with 1% Azone to enhance permeation, showed good skin permeability. ME-associated transdermal fluxes of schaftoside and isoschaftoside, two major effective constituents of TFRA, were 3.72-fold and 5.92-fold higher, respectively, than those achieved using aqueous suspensions. In contrast, in vitro studies revealed that uptake by HaCaT and CCC-ESF-1 cells was lower with ME than with an aqueous suspension. Stratum corneum loosening and shedding was observed in nude mouse skin treated with ME, although ME produced no observable skin irritation in rabbits. These findings indicated that ME enhanced transdermal TFRA delivery effectively and showed good biocompatibility with skin tissue.

Evaluation of skin viability effect on ethosome and liposome-mediated psoralen delivery via cell uptake.

This study investigated the effect of skin viability on its permeability to psoralen delivered by ethosomes, as compared with liposomes. With decreasing skin viability, the amount of liposome-delivered psoralen that penetrated through the skin increased, whereas skin deposition of psoralen from both ethosomes and liposomes reduced. Psoralen delivery to human-immortalized epidermal cells was more effective using liposomes, whereas delivery to human embryonic skin fibroblast cells was more effective when ethosomes were used. These findings agreed with those of in vivo studies showing that skin psoralen deposition from ethosomes and liposomes first increased and then plateaued overtime, which may indicate gradual saturation of intracellular drug delivery. It also suggested that the reduced deposition of ethosome- or liposome-delivered psoralen in skin with reduced viability may relate to reduced cellular uptake. This work indicated that the effects of skin viability should be taken into account when evaluating nanocarrier-mediated drug skin permeation.

Comparison of ethosomes and liposomes for skin delivery of psoralen for psoriasis therapy.

Recent reports have indicated that psoriasis may be caused by malfunctioning dermal immune cells, and psoralen ultraviolet A (PUVA) is an effective treatment for this chronic disease. However, conventional topical formulations achieve poor drug delivery across patches of psoriasis to their target sites. The present study describes the development of a novel psoralen transdermal delivery system employing ethosomes, flexible vesicles that can penetrate the stratum corneum and target deep skin layers. An in vitro skin permeation study showed that the permeability of psoralen-loaded ethosomes was superior to that of liposomes. Using ethosomes, psoralen transdermal flux and skin deposition were 38.89±0.32 µg/cm(2)/h and 3.87±1.74 µg/cm(2), respectively, 3.50 and 2.15 times those achieved using liposomes, respectively. The ethosomes and liposomes were found to be safe following daily application to rat skin in vivo, for 7 days. The ethosomes showed better biocompatibility with human embryonic skin fibroblasts than did an equivalent ethanol solution, indicating that the phosphatidylcholine present in ethosome vesicles improved their biocompatibility. These findings indicated that ethosomes could potentially improve the dermal and transdermal delivery of psoralen and possibly of other drugs requiring deep skin delivery.

Evaluation of psoralen ethosomes for topical delivery in rats by using in vivo microdialysis.

This study aimed to improve skin permeation and deposition of psoralen by using ethosomes and to investigate real-time drug release in the deep skin in rats. We used a uniform design method to evaluate the effects of different ethosome formulations on entrapment efficiency and drug skin deposition. Using in vitro and in vivo methods, we investigated skin penetration and release from psoralen-loaded ethosomes in comparison with an ethanol tincture. In in vitro studies, the use of ethosomes was associated with a 6.56-fold greater skin deposition of psoralen than that achieved with the use of the tincture. In vivo skin microdialysis showed that the peak concentration and area under the curve of psoralen from ethosomes were approximately 3.37 and 2.34 times higher, respectively, than those of psoralen from the tincture. Moreover, it revealed that the percutaneous permeability of ethosomes was greater when applied to the abdomen than when applied to the chest or scapulas. Enhanced permeation and skin deposition of psoralen delivered by ethosomes may help reduce toxicity and improve the efficacy of long-term psoralen treatment.