[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.

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.

[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.

In vivo microdialysis for the evaluation of transfersomes as a novel transdermal delivery vehicle for cinnamic acid.

In this study, cinnamic acid-loaded transfersomes were prepared and dermal microdialysis sampling was used in Sprague-Dawley rats to compare the amount of drug released into the skin using transfersomes as transdermal carriers with that released on using conventional liposomes. The formulation of cinnamic acid-loaded transfersomes was optimized by a uniform design through in vitro transdermal permeation studies. Hydration time was confirmed as a significant factor influencing the entrapment efficiency of transfersomes, further affecting their transdermal flux in vitro. The fluxes of cinnamic acid from transfersomes were all higher than those from conventional liposomes, and the flux from the optimal transfersome formulation was 3.01-fold higher than that from the conventional liposomes (p < 0.05). An in vivo microdialysis sampling method revealed that the dermal drug concentrations from transfersomes applied on various skin regions were much lower than those required with conventional liposomes. After the administration of drug-containing transfersomes and liposomes on abdominal skin regions of rats for a period of 10 h, the Cmax of cinnamic acid from the compared liposomes was 3.21 ± 0.25 µg/mL and that from the transfersomes was merely 0.59 ± 0.02 µg/mL. The results suggest that transfersomes can be used as carriers to enhance the transdermal delivery of cinnamic acid, and that these vehicles may penetrate the skin in the complete form, given their significant deformability.

Preparation and in vitro anti-tumor properties of toad venom extract-loaded solid lipid nanoparticles.

In this study, we prepared solid lipid nanoparticles (TV-SLNs) loaded with toad venom extract and investigated their anti-tumor effects in vitro in HeLa and SKOV-3 cells. TV-SLNs were prepared using a cold homogenization technique, and the formulation was optimized by central composite design and response surface methods. The anti-tumor activities of TV-SLNs were evaluated by analyzing cell division and cell cycle distribution by using the MTT assay and flow cytometry. After incubation with TV-SLNs, the growth of both HeLa and SKOV-3 cells was inhibited significantly. The percentage of HeLa cells in G0/G1 phase decreased, whereas that in the S and G2/M phases increased. Thus, the S and G2/M phases were blocked after the incubation of HeLa cells with TV-SLNs for 24 h. In contrast, the percentage of SKOV-3 cells in G0/G1 phase increased and then decreased in S and G2/M phases, with the G0/G1 phase being blocked after incubation with TV-SLNs for 24 h. Our results demonstrate that TV-SLNs inhibited the fissiparism of HeLa and SKOV-3 cells in a time-and dose-dependent manner. TV-SLNs may be effective as a novel TV vaginal delivery system for the treatment of cervical and ovarian cancers.

[Effect of stability and dissolution of realgar nano-particles using solid dispersion technology].

OBJECTIVE: To improve the stability and dissolution of realgar nano-particles by solid dispersion. METHOD: Using polyethylene glycol 6000 and poloxamer-188 as carriers, the solid dispersions were prepare by melting method. XRD, microscopic inspection were used to determine the status of realgar nano-particles in solid dispersions. The content and stability test of As(2)0(3) were determined by DDC-Ag method. Hydride generation atomic absorption spectrometry was used to determine the content of Arsenic and investigated the in vitro dissolution behavior of solid dispersions. RESULT: The results of XRD and microscopic inspection showed that realgar nano-particles in solid dispersions were amorphous. The dissolution amount and rate of Arsenic from realgar nano-particles of all solid dispersions were increased significantly, the reunion of realgar nano-particles and content of As(2)0(3) were reduced for the formation of solid dispersions. CONCLUSION: The solid dispersion of realgar nano-particles with poloxamer-188 as carriers could obviously improve stability, dissolution and solubility.

[Study on the pharmacokinetics of tashinone II(A) -loaded polylactic acid nanoparticles in rabbit].

OBJECTIVE: To establish a HPLC method for measuring tashinone II(A) concentration in rabbit plasma and study the pharmacokinetics of tashinone II(A) -loaded polylactic acid nanoparticles and tashinone II(A) injection in rabbits. METHODS: A single dose of TS-PLA-NP and TS II(A) injection was administered to 8 healthy rabbits via the ear-edge vein, at the set time withdrew the blood and prepared. The concentrations of tashinone II(A) in plasma were measured by HPLC with gemfibrozil as the internal standard. The pharmacokinetic parameters of TS-PLA-NP and tashinone II(A) injection were calculated by program DAS2.0. RESULTS: The average retention times of gemfibrozil and tashinone II(A) were 10.5 and 14.5 min, respectively. The half-life was prolonged from 2. 573 h of free tashinone II(A) to 4. 117 h and MRT(0-infinity) from 2.585 h to 6.033 h. The max concentration of tashinone II(A) was reduced from 0.21 to 0.134 mg/L. CONCLUSION: The method for the pharmacokinetic research of tshinone II A in rabbit plasma is accuracy, rapid and sensitive. TS-PLA-NP shows significant characteristic of delayed-release.

An improved formulation screening and optimization method applied to the development of a self-microemulsifying drug delivery system.

This study focused on the development of an improved formulation screening and optimization method for a self-microemulsifying drug delivery system (SMEDDS). Solubility study and construction of a ternary phase diagram were carried out to determine the primary formulation components. Experimental design combined with a desirability study was employed to obtain the optimal formulation composition. The obtained bufalin SMEDDS formulation was Maisine 35-1 and Miglyol 812N (1 : 1, w/w) of 29.5%, Cremophor EL of 39.5%, and Transcutol P of 30.5%. It showed desired properties with droplet size of 33.9 nm; polydispersity index of 0.126; equilibrium solubility of 12.6 mg/ml, and 73.6% of soluble drug post-digestion. A rapid release of up to 21% occurred in the first 10 min. A bufalin SMEDDS was well absorbed at all intestinal segments. The absorption of bufalin from a SMEDDS was 2.38-fold higher than that of bufalin suspension in terms of relative bioavailability. The studies on solubility and ternary phase diagrams combined with experimental design may offer a valuable and efficient strategy for developing and optimizing a SMEDDS to obtain optimal formulations with desired characteristics.

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.

[Release kinetics of oridonin self-microemulsifying drug delivery system in vitro].

OBJECTIVE: To investigate the release characteristics and mechanism of oridnonin self-microemulsifying drug delivery system (SMEDDS) in vitro. METHOD: The concentration of oridonin was determined by HPLC. In vitro release studies were conducted by reverse dialysis technique. The effects of release medium, agitation rate and preparations on the oridonin release were studied. The similarity factor (f2) was applied to the release profile comparisons. Model fitting was used to determine the kinetics and mechanism. RESULT: The release media and agitation rate from 50-100 r x min(-1) had no distinctive effect on the oridonin release kinetics, which the similarity factors were greater than 50. The oridonin release profiles for oridonin SMEDDS and oridonin ethanol solution were similar. 65% of oridonin were released in 30 min for oridonin SMEDDS in pH 7.8 PBS. Oridonin SMEDDS fit the Hixson-Crowell model best. CONCLUSION: The release data from oridonin SMEDDS showed it release fast. The deduced release mechanism is that the surface and particle sizes of self-microemulsion in water solution are changing during the process of release and the drug penetration through membrane is a passive diffusion process.

[Determination of vitexin-rhamnoside in Beagle dog plasma and preliminary pharmacokinetics of Yixintong sustained release tablets].

OBJECTIVE: To develop an HPLC method to determine vitexin-rhamnoside in plasma of Beagle dogs and study the pharmacokinetics and bioavailability of Yixintong sustained release tablets in Beagle dogs. METHOD: A newly-developed HPLC method using C18 column and methanol-acetonitrile-tetrahydrogenfuran-0.5% acetic acid (1:1:19.4:78.6) as mobile phase was validated, and then was employed to determine vitexin-rhamnoside in plasma of Beagle dogs after oral administration of Yixintong sustained release tablets and general tablets. The main pharmacokinetic parameters were estimated by pharmacokinetic program 3p87. The non-compartmental pharmacokinetic parameters were also calculated on basis of the statistic moment theory. RESULT: The pharmacokinetic profiles of Yixintong sustained release tablets and the general tablets were fitted to a one-and two-compartment open model, respectively. The T1/2, Tmax, AUC0-infinity and MRT for Yixintong sustained release tablets were 5.22 h, 4.0 h, 6,792.75 ng x h x mL(-1) and 8.4 h, respectively, compared with 8.94 h, 1.0 h, 5,880.4 ng x h x mL(-1) and 6.1 h for the general tablets. The relative bioavailability of the Yixintong sustained release tablets was 115.5% in Beagle dogs. CONCLUSION: The sustained-release characteristic of Yixintong sustained release tablets were confirmed by pharmacokinetic study.

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.

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.