Xin-An Wu

Lanzhou University, Lanzhou, Gansu Sheng, China

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Publications (10)9.97 Total impact

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    ABSTRACT: Renal tubular secretion is an important pathway for the elimination of many clinically used drugs. Metformin, a commonly prescribed first-line antidiabetic drug, issecretedprimarily by therenal tubule. Many patients with type 2 diabetes mellitus (T2DM) receiving metformin may together be given selective β1 blockers (e.g., atenolol). Therefore, it is of great use to evaluate the effect of atenolol on metformin urinary excretion for exploring drug interactions and predicting the adverse effect of drugs. The aim of this study was to investigate the effect of atenolol on the pharmacokinetic of metformin and plasma lactate (LCA) level in rats, for high LCA is a serious adverse reaction ofmetformin after long-term metformin treatment. In this study, rats were treated with metformin alone or in combination with atenolol. Plasma, urine and tissue concentration of metformin was determined by HPLC method, while Western blotting and immunohistochemical analysis were used to evaluate the renal expression of rat organic cation transporter 2 (rOct2) and multidrug and toxin extrusion protein 1 (rMate1). The results showed that, after 7 days drug treatment, the AUC0→t of metformin in atenolol and metformin co-administration group was significantly increased by 19.5% compared to that in metformin group, while the 24 h cumulative urinary excretion of metformin was significantly decreased by 57.3%. In addition, atenolol treatment significantly decreased the renal expression of rMate1, but had no effect on rOct2 expression, renal blood perfusion and glomerular filtration. Moreover, plasma LCA level in atenolol and metformin co-administration group rats was significantly increased by 83.3% compared to that in metformin group after 60 days drug treatment. These results indicated that atenolol can inhibit urinary excretion of metformin via decreasing renal rMate1 expression, and long-term atenolol and metformin co-administration may induce potential lactic acidosis. Our results, for the first time, provided an important experimental evidence that rMate1 is the target of transporter-mediated drug interactions concerning metformin and atenolol. Copyright © 2014. Published by Elsevier B.V.
    European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 12/2014; · 2.61 Impact Factor
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    ABSTRACT: The study aims to establish a method for simultaneous determination of repaglinide and pravastatin sodium in rat plasma by LC-MS/MS and to study its pharmacokinetic interactions. Eighteen male SD rats were divided into repaglinide group, pravastatin sodium group and co-administration group. Blood samples were collected at different times after oral administration. Repaglinide and pravastatin sodium in rat plasma were separated by Agilent HC-C18 with the mobile phase consisting of methanol-0.1% formic acid (80 : 20). Detection and quantification were performed by using ESI-MS. The detector was operated in selected Reaction-monitoring mode at m/z 453.3-->230.1 for repaglinide, m/z 447.2-->327.4 for pravastatin sodium and m/z 285.1-->192.9 for diazepam as the internal standard. The calibration curve obtained was linear (R2>0.99) over the concentration range of 9.77-10,000 ng.mL-1 for repaglinide and 4.88-625 ng.mL-1 for pravastatin sodium. Compared with the single administration group, Cmax and AUC0-6h of repaglinide increased significantly (P<0.05) and tmax of pravastatin sodium prolonged (P<0.05) in co-administration group. The method is found to be simple, sensitive and accurate for determining the concentration of repaglinide and pravastatin sodium in rat plasma. There exists pharmacokinetic interactions in the co-administration of repaglinide and pravastatin sodium.
    Yao xue xue bao = Acta pharmaceutica Sinica 01/2014; 49(1):72-7.
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    ABSTRACT: In this review, we have highlighted the adverse drug reaction mediated by transporters from two aspects: (1) competitive interactions between drug and drug/metabolite/endogenous substance mediated by transporters; (2) the expression/function change of transporter due to physiologic factors, disease, and drugs induction. It indicated that transporters exhibited a broad substrate specificity with a degree of overlap, which could change the pharmacokinetics of drugs and cause toxicity due to competition interactions among substrates. In addition, the expression and function of transporters were regulated by physiological conditions, pathological conditions, and drugs induction, which could cause adverse drug reaction and interindividual differences. Furthermore, one substrate was always medicated by several transporters and often subjected to metabolism by CYP enzymes, so we should be more aware of the increased plasma concentration of drugs caused by drug transporters as well as drug metabolizing enzymes synergistically, especially for drugs with narrow therapeutic window. In addition, the weightiness for one transporter to induce drugs plasma/tissue concentration change could be different in different condition. On the whole, transporters were corresponding with systemic/organs exposure of drug/metabolites/endogenous compounds. So understanding the expression and function in drug transporters will result in better strategies for optimal dosage regimen and reduce the risk for drug adverse reaction as well as adverse drug-drug interactions.
    European Journal of Drug Metabolism and Pharmacokinetics 01/2013; · 1.31 Impact Factor
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    ABSTRACT: Pyridoxine is always simultaneously administered orally with isoniazid for tuberculosis patients in the clinic to prevent or treat the nervous system side effects induced by isoniazid. So the aim of this research was to investigate the effects of pyridoxine on the intestinal absorption and pharmacokinetics of isoniazid. The intestinal absorption of isoniazid with or without pyridoxine was investigated by the rat single-pass intestinal perfusion model in situ, and a high-performance liquid chromatographic method was applied to study the pharmacokinetics of isoniazid with or without pyridoxine. The results suggested that the intestinal apparent permeability (P (app)) and intestinal absorption rate constant (K (a)) for isoniazid (30 μg/ml) were decreased by 43.7 and 36.4 %, respectively, by co-perfused pyridoxine (40 μg/ml). In vivo, the effect of pyridoxine on isoniazid pharmacokinetic correlated with the doses of pyridoxine. The blood concentrations of isoniazid at the absorption phase were affected by co-administered pyridoxine, but the AUC and C (max) of isoniazid were not greatly affected by pyridoxine as expected from the inhibition by pyridoxine of the intestinal absorption of isoniazid, which could be caused by its rapid absorption phase. Therefore, although the intestinal absorption of isoniazid could be significantly inhibited by pyridoxine, the pharmacokinetics of isoniazid oral administration was not greatly affected by the decreased intestinal absorption of isoniazid due to its rapid absorption.
    European Journal of Drug Metabolism and Pharmacokinetics 10/2012; · 1.31 Impact Factor
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    ABSTRACT: The present study aimed to investigate the pharmacokinetic variation of ofloxacin based on gender-related difference in the expression of multidrug resistance-associated protein (Abcc2/Mrp2) in rat kidney. The concentrations of ofloxacin in rat plasma and urine were determined after tail vein administration (30 mg x kg(-1)) by high-performance liquid chromatography (HPLC) method. Expression of Mrp2 in kidney of male and female rats was qualitatively and quantitatively detected by immunohistochemistry and flow cytometry, separately. The results showed that AUC value of ofloxacin was lower in male rats than that in female rats and the total amount of ofloxacin excreted in the urine was higher in male rats than that in female rats. And the expression of Mrp2 in male rat kidney was higher than that in female rats. All results suggested that gender-related differences in pharmacokinetics of ofloxacin may be attributed to the differences in the expression of Mrp2 in kidney of male and female rats.
    Yao xue xue bao = Acta pharmaceutica Sinica 05/2012; 47(5):624-9.
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    ABSTRACT: The aim of this study was to compare the skin permeation of ethosomes, binary ethosomes and transfersomes of Terbinafine Hydrochloride (TH) under non-occlusive conditions. These lipid vesicles were prepared and characterized for shape, size, zeta-potential and entrapment efficiency. Franz diffusion cells and confocal laser scanning microscopy (CLSM) were used for the percutaneous absorption studies. The quantity of drug in the skin from ethosomes, binary ethosomes (the weight ratio of ethanol to propylene glycol 7:3, ethanol-PG = 7:3, w/w), and transfersomes was 1.26, 1.51 (p <0.05), 1.56 (p <0.01) times higher than that of TH from traditional liposomes (control). The skin deposition of the applied dose (DD%) of TH from ethosomes, binary ethosomes, and transfersomes was 3.34 (p < 0.05), 9.88 (p < 0.01), 2.52 times higher than that of TH from control. The results of CLSM experiments showed that penetration depth and fluorescence intensity of Rhodamine B from binary ethosomes was much greater than that from ethosomes and transfersomes. These results indicated the binary ethosomes (ethanol-PG = 7:3, w/w) most effectively permitted drug penetration through skin; transfersomes made drug easiest to accumulate in the skin. Ethosomes improved drug delivery with greater improvement in skin permeation than improvement in skin deposition.
    Archives of Pharmacal Research 01/2012; 35(1):109-17. · 1.54 Impact Factor
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    ABSTRACT: The aim of this study was to investigate the lipophilic prodrug as a means of promoting acyclovir (ACV) that exhibited biphasic insolubility into the ethosomes for optimum skin delivery. Acyclovir Palmitate (ACV-C(16)) was synthesized as the lipophilic prodrug of ACV. The ethosomal system and the liposomal system bearing ACV or ACV-C(16) were prepared, respectively. The systems were characterized for shape, zeta potential value, particle size, and entrapment efficiency. Franz diffusion cells and confocal laser scanning microscopy were used for the percutaneous absorption studies. The results showed that the entrapment efficiency of ACV-C(16) ethosomes (87.75%) were much higher than that of ACV ethosomes (39.13%). The quantity of drug in the skin from ACV-C(16) ethosomes at the end of the 24 h transdermal experiment (622.89 microg/cm(2)) was 5.30 and 3.43 times higher than that from ACV-C(16) hydroalcoholic solution and ACV ethosomes, respectively. This study indicated that the binary combination of the lipophilic prodrug ACV-C(16) and the ethosomes synergistically enhanced ACV absorption into the skin.
    Archives of Pharmacal Research 04/2010; 33(4):567-74. · 1.54 Impact Factor
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    ABSTRACT: Solid dispersions (SDs) of aloe-emodin (AE) and polyethylene glycol 6000 (PEG6000) with different drug loadings were prepared, characterized by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) and evaluated for solubility and in vitro release. The oral bioavailability of AE from SD in rats was compared with the crystalline drug. Plasma concentrations of AE were determined by HPLC. After administration of crystalline AE (35 mg·kg−1) in rats, the AUC0-600 and Cmax were 393.6±77.1 mg·min·l−1 and 1.87±0.30 mg·l−1, respectively. For the PEG6000 SD of AE, AUC0-600 and Cmax were boosted to 1310.5±111.9 mg·min·l−1 and 5.86±0.47 mg·l−1, respectively. The results indicated that the oral bioavailability of AE was increased significantly. Simultaneously, the Tmax value of AE for AE crystalline was decreased from 75.6±17.3 min to 44.8±14.8 min for SD. The earlier Tmax for AE from SD indicated the higher extent of absorption for SD due to their improved dissolution rate in rat intestine. This SD approach can therefore be used to enhanced dissolution and bioavailability for poorly water-soluble drugs. Drug Dev Res, 2009. © 2009 Wiley-Liss, Inc.
    Drug Development Research 06/2009; 70(5):363 - 369. · 0.87 Impact Factor
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    ABSTRACT: This paper describes a rapid and sensitive high-performance liquid chromatographic (HPLC) method for the determination of the concentration of tanshinone I in rat plasma, and applies the method to pharmacokinetic study. The plasma is deproteinized with acetonitrile containing an internal standard (estradiolbenzoate). The HPLC assay is carried out using a Cosmosil C18 column. The mobile phase is acetonitrile, 0.05 mol/L(-1) ammonium acetate buffer with 1% acetic acid (66:34, v/v). The flow rate is 1.0 mL/min. The detection wavelength is set at 263 nm. The assay accuracy is better than 92%, and the precision of tanshinone I at low to high concentrations is better than 9% and 11% for intra-day and inter-day assays, respectively. The recovery of the method exceeds 88.3% for tanshinone I. The assay shows good linearity (r = 0.9998) over a relatively wide concentration range from 0.05 to 10.0 microg/mL. The method is used to determine the concentration-time profiles of tanshinone I in plasma following an intravenous injection of tanshinone I solution, and the pharmacokinetic parameters of tanshinone I are calculated for the first time by the Drug and Statistics 1.0 program. This assay is successfully applied to the determination of tanshinone I in rat plasma, and the developed method is applied to pharmacokinetic studies for the first time.
    Journal of chromatographic science 10/2008; 46(8):730-4. · 0.79 Impact Factor
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    ABSTRACT: To study effects of Yuquan pills on the pharmacokinetics process of metformin hydrochloride in diabetic rats. After administration Yuquan pills 7 day to the diabetic rats, the metformin hydrochloride was orally administrated, then the blood samples were collected at different time. The concentrations of metformin hydrochloride in plasma were determined by HPLC method and the pharmacokinetic parameters were calculated. The pharmacokinetic parameter Cmax of the controlling group and the testing group were respectively, 18.95, 21.76 mg x L(-1); t1/2 were 1,069.8, 1,767.4 min, respectively; CL/F were 0.013, 0.008 L x min(-1) x kg(-1); AUC were 10,042.1, 10,712.2 mg z L(-1) x min(-1) respectively. The pharmacokinetics process of metformin hydrochloride in diabetic rats fits one-compartment model. Yuquan pills has a significant effect on the pharmacokinetics of metformin hydrochloride in diabetic rats.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 10/2008; 33(18):2133-5, 2139.