Formulation and Characterization of Hydroquinone Nanostructured Lipid Carriers by Homogenization Emulsification Method

Nanostructured lipid carrier (NLC) was prepared by homogenization emulsification method and improved with modified surfactants. The properties of nanoparticles were investigated using the NLC system for hydroquinone (HQ) as a model drug and by increasing the light stability of hydroquinone. The optimized condition of NLC in stirring was 1200 rpm, the homogenized speed was 8000 rpm, solid oil to liquid oil ratio was 3 : 7, and lecithin to surfactant ratio was 3 : 1. The particle size was 393.30±28.23 nm and the encapsulation efficiency was 22.13±2.66%. The zeta-potential of HQ-NLC was better than −30 mV. In the thermogravimetric analysis (TGA) studies, adding of PLANTACARE 2000 UP for HQ-NLC has better heat resisting property than the HQ-NLC only. The addition of PLANTACARE 2000 UP to NLC shows better permeability (125.10%) than that of Blank. In the stability studies, the HQ-NLC after UVA/UVB irradiation has better inhibition rate (34.25%) than that of the Blank. In the present study, NLC system has successfully improved the light stability and the skin permeability of active compound. Therefore, the NLC might be a potential delivery vehicle for transdermal products in the future

Green tea inhibited the elimination of nephro-cardiovascular toxins and deteriorated the renal function in rats with renal failure

Chronic kidney disease (CKD) is a major health problem worldwide. Indoxyl sulfate (IS) and p-cresyl sulfate (PCS) are highly protein-bound nephro-cardiovascular toxins, which are not efficiently removed through hemodialysis. The renal excretions of IS and PCS were mediated by organic anion transporters (OATs) such as OAT1 and OAT3. Green tea (GT) is a popular beverage containing plenty of catechins. Previous pharmacokinetic studies of teas have shown that the major molecules present in the bloodstream are the glucuronides/sulfates of tea catechins, which are putative substrates of OATs. Here we demonstrated that GT ingestion significantly elevated the systemic exposures of endogenous IS and PCS in rats with chronic renal failure (CRF). More importantly, GT also significantly increased the levels of serum creatinine (Cr) and blood urea nitrogen (BUN) in CRF rats. Mechanism studies indicated that the serum metabolites of GT (GTM) inhibited the uptake transporting functions of OAT1 and OAT3. In conclusion, GT inhibited the elimination of nephro-cardiovascular toxins such as IS and PCS, and deteriorated the renal function in CRF rats

Study on the Stability of DeoxyArbutin in an Anhydrous Emulsion System

The skin-whitening agent, deoxyArbutin, is a potent tyrosinase inhibitor that is safer than hydroquinone and arbutin. However, it is thermolabile in aqueous solutions, where it decomposes to hydroquinone. Pharmaceutical and cosmetic emulsions are normally oil-in-water (o/w) or water-in-oil (w/o) systems; however, emulsions can be formulated with no aqueous phase to produce an anhydrous emulsion system. An anhydrous emulsion system could offer a stable vehicle for compounds that are sensitive to hydrolysis or oxidation. Therefore, to enhance the stability of deoxyArbutin in formulations, we chose the polyol-in-silicone, anhydrous emulsion system as the basic formulation for investigation. The quantity of deoxyArbutin and the accumulation of hydroquinone in both hydrous and anhydrous emulsions at various temperatures were analyzed through an established high performance liquid chromatographic (HPLC) method. The results indicated that water increased the decomposition of deoxyArbutin in the formulations and that the polyol-in-silicone, oil-based, anhydrous emulsion system provided a relatively stable surrounding for the deoxyArbutin that delayed its degradation at 25 °C and 45 °C. Moreover, the composition of the inner hydrophilic phase, containing different amounts of glycerin and propylene glycol, affected the stability of deoxyArbutin. Thus, these results will be beneficial when using deoxyArbutin in cosmetics and medicines in the future

Different Influences on Tacrolimus Pharmacokinetics by Coadministrations of Zhi Ke and Zhi Shi in Rats

Tacrolimus, an immunosuppressant with narrow therapeutic window, has been used widely in transplant patients. Grapefruit juice and pomelo have been reported to increase the blood levels of tacrolimus. Zhi Ke and Zhi Shi, the ripe peels and unripe fruits of Citrus aurantium which is chemotaxonomically related to grapefruit and pomelo, are in wide use in clinical Chinese medicine. To investigate the possible interaction of these two Citrus herbs with tacrolimus, male Sprague-Dawley rats were orally given tacrolimus (1.5 mg/kg) with and without Zhi Ke and Zhi Shi decoctions in a cross-over design. Blood samples were withdrawn via cardiopuncture at specific time and quantitated by a microparticle enzyme immunoassay. In addition, to explore the mechanism of interaction, LS 180 cell line was used for the transport study of rhodamine 123, a typical substrate of P-glycoprotein (P-gp). The results showed that Zhi Shi significantly decreased the Cmax and AUC0−t of tacrolimus by 72.4% and 72.0%, respectively, whereas Zhi Ke did not affect tacrolimus pharmacokinetics. LS 180 cell line study indicated that Zhi Shi increased the efflux activity of P-gp, enabling us to explain the decreased oral bioavailability of tacrolimus caused by Zhi Shi. Hence, we suggest that Zhi Shi be contraindicated for transplant patients treated with tacrolimus to reduce the risk of allograft rejection

The Competency for Taiwanese Bank Expatriate Managers in China

[[abstract]]To expand the market share, Taiwanese banks has increasingly invested in China. In this start-up period, many managers were sending from Taiwan to China for running the business. The issues of managing expatriates have drawn attentions. To investigate the current situation of expatriate management of the Taiwanese banks to China, this study interviewed the business practitioners to portrait the general pictures of the following focuses: 1.The selection criteria for the Taiwanese bank expatriate managers assigned to China. 2.The roles and tasks for the Taiwanese bank expatriate managers assigned to China. 3.The required competencies for the Taiwanese bank expatriate managers assigned to China. 4.The content of training programs for the Taiwanese bank expatriate managers assigned to China. Base on the contents retrieved from the selection criteria, roles and tasks and content of training program, the study generated the required knowledge, skills, experiences and personality traits for the expatriate managers as a reference resource for the Taiwanese banks that designate expatriate to China. Keywords: competency, competency models, expatriate manager, banks

Development of Octyl Methoxy Cinnamates (OMC)/Silicon Dioxide (SiO2) Nanoparticles by Sol-Gel Emulsion Method

Although octyl methoxy cinnamates (OMC) is the most used Ultraviolet B (UVB) filter in sunscreen, it has poor light stability in emulsion system. In this study, OMC/SiO2 nanoparticles were prepared via sol-gel emulsion method. Tetraethoxy silane (TEOS) was used as the silica source to encapsulate OMC. Modification of experimental parameters such as stirring speed of condensation reaction and emulsion condition, pH value of acid-catalyzed, surfactant and different percentage of TEOS and OMC, adding of OMC and surfactant to different phase may affect the particle size, and yield and entrapment efficiency in preparation process of OMC/SiO2 nanoparticles. Concluding all the parameter, we found that when condensation reaction and emulsion conditions are at 1000 rpm, pH 1.5, Span 80/Tween 20, TEOS/OMC ratios 1:1, OMC and surfactants added in oil phase, resulting in smaller particle sizes 476.5 nm, higher yield 95.8%, and higher entrapment efficiency 61.09%. Fourier transform infrared (FTIR) analysis demonstrated that OMC/SiO2 nanoparticles were successfully prepared. In vitro release profile supposed that OMC/SiO2 nanoparticles can delay OMC releasing and had 60.83% decreasing of cumulative amount. Therefore, the OMC/SiO2 nanoparticles have the potential to develop as new sunscreen materials in the use for cosmetics field in the future

Activation of P-glycoprotein and CYP 3A by Coptidis Rhizoma in vivo: Using cyclosporine as a probe substrate in rats

Coptidis Rhizoma (CR), the rhizome of Coptis chinensis FRANCH, is a popular Chinese herb. CR contains plenty of isoquinoline alkaloids such as berberine, coptisine and palmatine. Cyclosporine (CSP), an important immunosuppressant with narrow therapeutic window, is employed as a probe substrate of P-glycoprotein (P-gp) and CYP3A4 in order to investigate the in vivo modulation effect of CR on P-gp and CYP3A4. Three groups of rats were orally administered CSP without and with single dose or repeated dosing of CR in a parallel design. Blood samples were collected at specific time points and the blood CSP concentration was determined by a specific monoclonal fluorescence polarization immunoassay. The results showed that a single dose (1.0 g/kg) and the 7th dose (1.0 g/kg) of CR significantly decreased the Cmax of CSP by 56.9% and 70.4%, and reduced the AUC0-540 by 56.4% and 68.7%, respectively. Cell study indicated that CR decoction, berberine, coptisine, palmatine all activated the efflux transport of P-gp. Ex-vivo study showed that the serum metabolites of CR activated CYP 3A4. In conclusion, through using CSP as an in vivo probe substrate, we have verified that oral intake of CR activated the functions of P-gp and CYP3A based on in vivo and in vitro studies. Keywords: Cyclosporine, P-glycoprotein, Cytochrome P450 3A, Herb–drug interactions, Pharmacokinetic

Magnolol and Honokiol Inhibited the Function and Expression of BCRP with Mechanism Exploration

Breast cancer resistance protein (BCRP), one of the ATP-binding cassette (ABC) transporters, was associated with the multidrug resistance (MDR) of chemotherapy. Magnolol (MN) and honokiol (HK) are major bioactive polyphenols of Magnolia officinalis. This study investigated the effects of MN and HK on the function and expression of BCRP for the purpose of developing BCRP inhibitor to overcome MDR. Cell lines including MDCKII-BCRP and MDCKII-WT were used for evaluating the function and expression of BCRP. The results showed that MN (100–12.5 µM) and HK (100–12.5 µM) significantly decreased the function of BCRP by 80~12% and 67~14%, respectively. In addition, MN and HK were verified as substrates of BCRP. Furthermore, MN and HK reduced the protein expression of BCRP, and inhibited the phosphorylation of epidermal growth factor receptor (EGFR) and phosphatidylinositol 3-kinase (PI3K). In conclusion, both MN and HK decreased the function and expression of BCRP via EGFR/PI3K signaling pathway. Therefore, both compounds were promising candidates for reversing the MDR of chemotherapy

Bidirectional Influences of Cranberry on the Pharmacokinetics and Pharmacodynamics of Warfarin with Mechanism Elucidation

Cranberry is a dietary supplement popularly used for the prophylaxis of urinary tract infection. Interestingly, cranberry–warfarin interactions in clinical reports have shown bidirectional outcomes. (±) Warfarin, a widely prescribed anticoagulant, but with a narrow therapeutic index, contains equal amounts of S- and R-warfarin, of which S-warfarin is more active. The aim of this study was to investigate the effects of different ingestion times of cranberry on the pharmacokinetics and pharmacodynamics of warfarin. Rats were orally administered (±) warfarin (0.2 mg/kg) with and without cranberry (5.0 g/kg) at 0.5 h prior to the warfarin, and at 10 h after the warfarin. The plasma concentrations of S- and R-warfarin were determined by LC/MS. The results indicate that cranberry ingested at 0.5 h before (±) warfarin significantly decreased the systemic exposures of S-warfarin and R-warfarin. Conversely, when cranberry was ingested at 10 h after (±) warfarin, the elimination of S-warfarin was significantly inhibited, and the anticoagulation effect of (±) warfarin was significantly enhanced. The results of the mechanism studies indicate that cranberry activated the breast cancer resistance protein (BCRP), which mediated the efflux transports of S-warfarin and R-warfarin. Moreover, the metabolites of cranberry inhibited cytochrome P450 (CYP) 2C9, the main metabolizing enzyme for S-warfarin. In conclusion, cranberry affected the pharmacokinetics of (±) warfarin in a bidirectional manner by activating the BCRP by CJ during absorption and inhibiting the BCRP and CYP2C9 by CMs during elimination, depending on the ingestion time of CJ. The combined use of cranberry with warfarin should be avoided

Preparation and Evaluation of Novel Transfersomes Combined with the Natural Antioxidant Resveratrol

Resveratrol (tran-3,5,4′-trihydroxystibene, RSV) is a kind of polyphenol which has anti-inflammatory, antioxidant, anti-allergy, and anti-cancer properties, as well as being a scavenger of free radicals and preventing cardiovascular diseases. However, it is quite unstable in light, heat, and other conditions, and decays easily due to environmental factors. For these reasons, this study used a new type of carrier, transfersome, to encapsulate RSV. Transfersome consists of phosphatidyl choline (PC) from a liposomal system and non-ionic edge activators (EA). EA are an important ingredient in the formulation of transfersome; they can enhance the flexibility of the lipid bimolecular membrane of transfersome. Due to its ultradeformability, it also allows drugs to penetrate the skin, even through the stratum corneum. We hope that this new encapsulation technique will improve the stability and enhance the permeability of RSV. Concluding all the tested parameters, the best production condition was 5% PC/EA (3:1) and 5% ethanol in distilled water, with an ultrasonic bath and stirring at 500 rpm, followed by high pressure homogenization. The optimal particle size was 40.13 ± 0.51 nm and the entrapment efficiency (EE) was 59.93 ± 0.99%. The results of antioxidant activity analysis showed that transfersomes were comparable to the RSV group (unencapsulated). During in vitro transdermal delivery analysis, after 6 h, D1-20(W) increased 27.59% by accumulation. Cell viability assay showed that the cytotoxicity of D3-80(W) was reduced by 34.45% compared with the same concentration of RSV. Therefore, we successfully prepared RSV transfersomes and also improved the stability, solubility, and safety of RSV