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- Establishment of novel prediction system of intestinal absorption in humans using human intestinal tissues. [JOURNAL ARTICLE]
- J Pharm Sci 2013 May 19.
The objective of this study was to establish a novel prediction system of drug absorption in humans by utilizing human intestinal tissues. Based on the transport index (TI), a newly defined parameter, calculated by taking account of the change in drug concentrations because of precipitation on the apical side and the amounts accumulated in the tissue and transported to the basal side, the absorbability of drugs in rank order as well as the fraction of dose absorbed (Fa) in humans were estimated. Human intestinal tissues taken from ulcerative colitis or Crohn's disease patients were mounted in a mini-Ussing chamber and transport studies were performed to evaluate the permeation of drugs, including FD-4, a very low permeable marker, atenolol, a low permeable marker, and metoprolol, a high permeable marker. Although apparent permeability coefficients calculated by the conventional equation did not reflect human Fa values for FD-4, atenolol, and metoprolol, TI values were well correlated with Fa values, which are described by 100 · [1 - e (- f · (TI - α)) ]. Based on this equation, Fa values in humans for other test drugs were predicted successfully, indicating that our new system utilizing human intestinal tissues would be valuable for predicting oral drug absorption in humans. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci.
- Mechanism considerations for photocatalytic oxidation, ozonation and photocatalytic ozonation of some pharmaceutical compounds in water. [JOURNAL ARTICLE]
- J Environ Manage 2013 May 16.:114-124.
Aqueous solutions of four pharmaceutical compounds, belonging to the group of emergent contaminants of water: atenolol (ATL), hydrochlorothiazide (HCT), ofloxacin (OFX) and trimethoprim (TMP), have been treated with different oxidation systems, mainly, photocatalytic oxidation, ozonation and photocatalytic ozonation. TiO2 has been used as semiconductor for photocatalytic reactions both in the presence of air, oxygen or ozone-oxygen gas mixtures. Black light lamps mainly emitting at 365 nm were the source of radiation. In all cases, the influence of some variables (concentrations of semiconductor, ozone gas and pharmaceuticals and pH) on the removal of pharmaceuticals, total polyphenol content (TPC) and total organic carbon (TOC) was investigated. A discussion on the possible routes of pharmaceutical and intermediates (as TPC and TOC) elimination has been developed. Thus, OFX TiO2/UVA degradation mechanism seems to develop through the participation of non-hydroxyl free radical species. Furthermore, the presence of OFX inhibits the formation of hydroxyl radicals in the photocatalytic process. The most effective processes were those involving ozone that lead to complete disappearance of parent compounds in less than 30 min for initial pharmaceutical concentrations lower than 2.5 mg L(-1). In the ozonation systems, regardless of the pH and the presence of TiO2, pharmaceuticals are degraded through their direct reaction with ozone. Photocatalytic ozonation was the most efficient process for TPC and TOC removals (≥ 80% and ≥60% elimination after 2 h of treatment, respectively) as well as in terms of the ozone consumption efficiency (1, 5.5 and 4 mol of ozone consumed per mol of TOC mineralized, at pH 4, 7 and 9, respectively). Weakly acid conditions (pH 4) resulted to be the most convenient ones for TPC and TOC removal by photocatalytic ozonation. This was likely due to formation of hydroxyl radicals through the ozonide generated at these conditions.
- Effect of treatment with atenolol on 5-year survival in cats with preclinical (asymptomatic) hypertrophic cardiomyopathy. [JOURNAL ARTICLE]
- J Vet Cardiol 2013 May 15.
OBJECTIVES:To investigate the effect of treatment with atenolol on 5-year survival in cats with preclinical hypertrophic cardiomyopathy (HCM).
ANIMALS:63 Client-owned cats with preclinical HCM and 31 healthy control cats.
METHODS:Prospective, observational, open-label, clinical cohort study. Cats with HCM were diagnosed by echocardiography, treated with atenolol (6.25-12.5 mg q12h, PO; n = 42) or untreated (n = 21), and were observed for 5 years after enrollment. The study end point was death from any cause. Cats of similar body weight, age, gender, and breed without evidence of heart disease were studied concurrently and served as controls.
RESULTS:During the observational period, 27 cats with HCM died; 14 (22%) due to cardiac disease and 13 (21%) due to non-cardiac disease. Ten control cats (32%) died of non-cardiac disease. There was no significant difference (P = 0.307) in all-cause mortality between control and HCM. Cardiac mortality was higher in cats with HCM compared to control cats (P = 0.005). There was no significant difference in all-cause mortality (P = 0.729) and cardiac mortality (P = 0.897) between cats with HCM treated or untreated with atenolol. Age and left atrial size at diagnosis were the only predictors of 5-year outcome.
CONCLUSIONS:Our study failed to demonstrate an effect of atenolol on 5-year survival in cats with preclinical HCM.
- [Simultaneous determination of 18 pharmaceuticals and personal care products in surface water by ultra-high performance liquid chromatography-tandem mass spectrometry]. [English Abstract, Journal Article]
- Se Pu 2013 Jan; 31(1):15-21.
An analytical method has been developed and validated for the simultaneous determination of 18 pharmaceuticals and personal care products (PPCPs), including antibiotics (trimethoprim, erythromycin x 2H2O, norfloxacin, ofloxacin, pencilline G, penicillin V potassium salt, cephalexin and sulfamethoxazole), beta-bloker (atenolol), anophelifuge (N, N-diethyl-3-methylbenzoylamide, DEET), antiepileptics (carbamazepine), central nervous system stimulant (caffeine), lipid modifying agent (clofibric acid), non-steroidal anti-inflammatory drugs (ibuprofen, naproxen and diclofenac sodium salt) and antimicrobial agents (triclosan and triclocarban). The detection and qualification of the target compounds were performed by ultra-high performance liquid chromatography-tandem mass spectrometry. The optimized mobile phases were methanol as organic phase, 0. 3% (v/v) formic acid-5 mmol/L ammonium acetate for positive electrospray ionization (ESI+) and 5 mmol/L ammonium acetate for ESI- as inorganic phase. Water samples were concentrated by solid phase extraction at 2 mL/min, and all the target PPCPs were efficiently extracted at pH 7. The extracted PPCPs were eluted by the mixture of methanol and acetonitrile (1 : 1, v/v). The average recoveries of the target compounds in the spiked pure water samples ranged from 53.9% - 112%. The average recoveries of the target compounds ranged from 45.1% - 156.6% with the relative standard deviations ranged from 2.4% - 15.7%, in the surface water samples spiked at 100 ng/L. The surface water samples collected from Yu Hangtang River in Hangzhou were detected. The results showed that nine PPCPs were detected including caffeine that reached a maximum concentration of 550.7 ng/L. It proved that this analytical method is reliable and acceptable.
- Simultaneous monitoring of photocatalysis of three pharmaceuticals by immobilized TiO2 nanoparticles: Chemometric assessment, intermediates identification and ecotoxicological evaluation. [JOURNAL ARTICLE]
- Spectrochim Acta A Mol Biomol Spectrosc 2013 Apr 11.:33-45.
In this study, the photocatalytic degradation of a mixture of three pharmaceuticals, Metronidazole (MET), Atenolol (ATL) and Chlorpromazine (CPR), was quantified simultaneously during the UV/TiO2 process. The investigated TiO2 was Millennium PC-500 immobilized on ceramic plates by sol-gel based method. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. The central composite design was applied to model and optimize the UV/TiO2 process. Predicted values of removal efficiency were found to be in good agreement with experimental values for MET, ATL and CPR (R(2)=0.947 and Adj-R(2)=0.906, R(2)=0.977 and Adj-R(2)=0.960 and R(2)=0.982 and Adj-R(2)=0.969, respectively). The optimum initial concentration of pharmaceuticals, reaction time and UV light intensity was found to be 10mgL(-1), 150min and 38.45Wm(-2), respectively. The main degradation intermediates of pharmaceuticals produced in this process were identified by GC-MS technique. The chronic ecotoxicity of pharmaceuticals was evaluated using aquatic species Spirodela polyrrhiza prior to and after photocatalysis. The TOC results (90% removal after 16h) and ecotoxicological experiments revealed that the photocatalysis process could effectively mineralize and reduce the ecotoxicity of the pharmaceuticals from their aqueous solutions.
- Equilibrium and release properties of hyaluronic acid-drug complexes. [JOURNAL ARTICLE]
- Eur J Pharm Sci 2013 May 6.
With the aim to provide more rational basis about the potentiality of hyaluronic acid (or hyaluronan) as drug carrier a set of ionic complexes of its acid form (HA) and its sodium salt (NaHA) with three model drugs (D) (atenolol, propranolol and lidocaine) were prepared. Besides NaHA subjected to hyalurodinase depolimerization (NaHAd) was also used. Transparent dispersions were obtained. They exhibited negative electrokinetic potential and a high degree of counterionic condensation with affinity constants (logKcc) in the range of 5.8-6.1 for propranolol complexes (pKa 9.45) and 4.0-4.6 for lidocaine ones (pKa 7.92). Delivery rates of D from the complexes were measured in a Franz-type bicompartimental device. Loaded D were slowly released from the three types of complexes, even when a neutral salt was added to the dispersion placed in the donor compartment, revealing the high affinity between the protonated drugs and the ionisable groups of the polymer. Complex dispersions based on HA or on NaHAd exhibited lower viscosity than those of NaHA but their complexing ability remained unaltered. The results reported on equilibrium and release properties of Hyaluronan-model D complexes contribute to expand the use of HA and NaHA as drug carriers for different routes of administration.
- Development and Characterization of Propranolol Selective Molecular Imprinted Polymer Composite Electrospun Nanofiber Membrane. [JOURNAL ARTICLE]
- AAPS PharmSciTech 2013 May 8.
Propranolol (PPL) imprinted microspheres (MIP) were successfully prepared via oil/water polymerization using a methyl methacrylate (MMA) monomer, PLL template, and divinylbenzene (DVB) cross-linker and favorably incorporated in a Eudragit-RS100 nanofiber membrane. A non-PPL imprinted polymer (NIP), without a template, was used as a control. The morphology and particle size of the beads were investigated using scanning electron microscopy. The results revealed that both MIP and NIP had a spherical shape with a micron size of approximately 50-100 μm depending on the amounts of DVB and PPL used. NIP2 (MMA/DVB, 75:2.5) and MIP8 (PPL/MMA/DVB, 0.8:75:2.5) were selected for reloading of PPL, and the result indicated that increasing the ratio of PPL to polymer beads resulted in increase PPL reloading (>80%). A total of 10-50% NIP2 or MIP8 was incorporated into a 40% (w/v) Eudragit-RS100 fiber membrane using an electrospinning technique. PPL could be bound to the 50% MIP8 composite fiber membrane with a higher extent and at a higher rate than the control (NIP2). Furthermore, the MIP8 composite fiber membrane showed higher selectivity to PPL than the other β-blockers (atenolol, metoprolol, and timolol). Thus, the MIP8 composite fiber membrane can be further developed for various applications in pharmaceutical and other affinity separation fields.
- Assessment of ABCG2-mediated transport of xenobiotics across the blood-milk barrier of dairy animals using a new MDCKII in vitro model. [JOURNAL ARTICLE]
- Arch Toxicol 2013 May 8.
The ATP-binding cassette (ABC) efflux transporter ABCG2 represents the main route for active secretion of drugs and toxins across the blood-milk barrier, thereby producing a potential health risk for dairy consumers through formation of relevant residues in milk. However, no suitable in vitro model is as yet available to systematically investigate ABCG2-mediated transport of xenobiotics into milk of dairy animals. We recently cloned ABCG2 from the lactating mammary gland of dairy cows (bABCG2) and goats (cABCG2). Thus, the objective of this study was to generate a suitable blood-milk barrier in vitro model using polarized MDCKII monolayers stably expressing mammary bABCG2 or cABCG2. ABCG2 protein was localized by confocal microscopy to the apical and lateral plasma membrane of polarized MDCKII cells. Intact barrier function of MDCKII-bABCG2 and MDCKII-cABCG2 monolayers was confirmed by determination of cell permeability of transcellular marker propranolol and paracellular marker atenolol which was ≤1 %. In flux assays, ABCG2 substrate 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) showed preferential basolateral to apical (B > A) transport in ABCG2-MDCKII cells. This apically directed PhIP transport was significantly inhibited by ABCG2 inhibitor fumitremorgin C (FTC) or the flavonoid equol. PhIP B > A transport in MDCKII-bABCG2 monolayers was additionally decreased by ABCG2 inhibitor Ko143. The fluoroquinolone antibiotic enrofloxacin was identified as a substrate of ruminant mammary ABCG2. The analgesic drug sodium salicylate was shown to be substrate of bABCG2 but not of cABCG2. Thus, the generated mammary ABCG2-expressing MDCKII cells represent a valuable tool to study active secretion of drugs and toxins into milk.
- Bisoprolol, ramipril and simvastatin determination in dried blood spot samples using LC-HRMS for assessing medication adherence. [Journal Article]
- J Pharm Biomed Anal 2013 Jul-Aug.:99-107.
The use of dried blood spot (DBS) collection cards was investigated for the quantification of three therapeutic drugs used in cardiovascular therapy for assessing medication adherence. A liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was developed and validated for the determination of bisoprolol, ramipril and simvastatin. Whole blood spiked with target analytes was used to produce 30μl blood spots on specimen collection cards. An 8mm disc was cut from the dried blood spot and extracted using methanol: water (70:30, v/v) containing the internal standard, atenolol. Extracts were vortexed, sonicated and then centrifuged. Gradient chromatographic elution was achieved using a Zorbax Eclipse C18 HD 100mm×2.1mm, 1.8μm pore size column and a mobile phase flow rate of 0.6ml/min and the column oven temperature at 40°C with a run time of 3min. MS detection was carried out in electrospray positive ion mode for the three target drugs and for the IS. Drug recoveries from spiked blood spots were ≥92% for bisoprolol and ramipril and ~43% for simvastatin and the drugs were stable in DBS for at least 12 weeks. Validation of the LC-HRMS method showed good linearity and the accuracy (relative error) and precision (coefficient of variation) values were within the pre-defined limits of ≤15% at all concentrations. Matrix effects and the effects of different volumes of blood applied to the collection card were investigated. The LC-HRMS method successfully identified control volunteers who were known to be either adherent or non-adherent. There were no false positives from volunteers taking other cardiovascular drugs or from volunteers receiving no medication.
- Multivariate curve resolution-alternating least squares assisted by voltammetry for simultaneous determination of betaxolol and atenolol using carbon nanotube paste electrode. [JOURNAL ARTICLE]
- Bioelectrochemistry 2013 Apr 12.
In the present work differential pulse voltammetry coupled with multivariate curve resolution-alternating least squares (MCR-ALS) was applied for simultaneous determination of betaxolol (Bet) and atenolol (Ate) in 0.20M Britton-Robinson (B-R) buffer solution at the surface of a multi-walled carbon nanotube modified carbon paste electrode (MWCNT/CPE). Characterization of the modified electrode was carried out by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). A strategy based on experimental design was followed. Operating conditions were improved with central composite rotatable design (CCRD) and response surface methodology (RSM), involving several chemical and instrumental parameters. Then second order data were built from variable pulse heights of DPV and after correction in potential shift analyzed by MCR-ALS. Analytical parameters such as linearity, repeatability, and stability were also investigated and a detection limit (DL) of 0.19 and 0.29μM for Bet and Ate was achieved, respectively. The proposed method was successfully applied in simultaneous determining the two analytes in human plasma.