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Synthesis of Depo‐Medrol–chitosan hydrogel as new drug slow‐release appliance and investigation of release kinetics by high‐performance liquid chromatography 下载免费PDF全文
Reza Alizadeh Sara Majd Jabbari Amir H. Zarnani Hamidreza Barghi 《Biomedical chromatography : BMC》2016,30(9):1346-1353
The present study deals with preparation and optimization of a novel chitosan hydrogel‐based matrix by suspension cross‐linking method for controlled release of Depo‐Medrol. The controlled release of Depo‐Medrol for effective Rheumatoid arthritis disease has become an imperative field in the drug delivery system. In this context, it was intended to optimize loading circumstances by experimental design and also study the release kinetics of Depo‐Medrol entrapped in the chitosan matrix in order to obtain maximal efficiency for drug loading. The optimum concentrations of chitosan (2.5 g), glutaraldehyde (3.05 μL) and Depo‐Medrol (0.1 mg) were set up to achieve the highest value of drug loaded and the most sustained release from the chitosan matrix. In vitro monitoring of drug release kinetic using high‐performance liquid chromatography showed that 73% of the Depo‐Medrol was released within 120 min, whereas remained drug was released during the next 67 h. High correlation between first‐order and Higuchi's kinetic models indicates a controlled diffusion of Depo‐Medrol through the surrounding media. Moreover, recovery capacity >82% and entrapment efficiency of 58–88% were achieved under optimal conditions. Therefore, the new synthesized Depo Medrol–chitosan is an applicable appliance for arthritis therapy by slow release mechanism. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Nonlinear Dynamics - A three-party-authenticated key agreement (3PAKA) scheme allows two participants to establish shared secure session key (3SK) via trusted server over a public network.... 相似文献
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Microchimica Acta - The authors describe a magnetic nanoadsorbent consisting of magnetite nanoparticles coated first with titanium dioxide and then with polypyrrole (PPy). It is shown to be a... 相似文献
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Ali Mehdinia Mina Asiabi Ali Jabbari 《International journal of environmental analytical chemistry》2015,95(12):1099-1111
A novel Fe3O4/graphene/polypyrrole nanocomposite has been successfully synthesised via a simple chemical method and applied as a new magnetic solid-phase extraction (MSPE) sorbent for the separation and pre-concentration of trace amounts of Pt (IV) in environmental samples followed by flame atomic absorption spectrometric (FAAS) detection. The nanocomposite has been characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Seven important parameters, affecting the extraction efficiency of Pt (IV), including pH, adsorption time, desorption solvent type and concentration, desorption time, elution volume and sample volume, were investigated. Under the optimised conditions, the calibration graph was linear in the range of 50–1500 μg L?1 (R = 0.993). The detection limit and pre-concentration factor (PF) for Pt (IV) were found to be 16 μg L?1 and 112.5, respectively. Under the optimised solid-phase extraction (SPE) conditions, the adsorption isotherm and the adsorption capacity of the nanocomposite for Pt (IV) were studied. Pt (IV) adsorption equilibrium data were fitted well to the Langmuir isotherm and the maximum adsorption capacity of the magnetic sorbent was calculated from the Langmuir isotherm model as 416.7 mg g?1. The precision of the method was studied as intraday and interday variations. A relative standard deviation percentage (RSD%) value less than 3.0 indicates that the method is precise. Also, the accuracy of the method was tested by the analysis of the standard reference material (NIST SRM 2556) and by recovery measurements on spiked real samples. It was also shown that the optimised method was suitable for the analysis of trace amounts of Pt (IV) in roadside soil, tap water and wastewater samples. 相似文献
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Electrocatalytic oxidation of the antiviral drug acyclovir on a copper nanoparticles-modified carbon paste electrode 总被引:1,自引:0,他引:1
H. Heli M. Zarghan A. Jabbari A. Parsaei A. A. Moosavi-Movahedi 《Journal of Solid State Electrochemistry》2010,14(5):787-795
The electrocatalytic oxidation of acyclovir (Zovirax) on two different copper-based electrodes: copper microparticles- and
copper nanoparticles-modified carbon paste electrodes (denoted as micro-CPE and nano-CPE, respectively) was voltammetrically
investigated. In the voltammogram recorded using micro-CPE, a single anodic oxidation peak appeared, while nano-CPE resulted
in two overlapped anodic peaks. The anodic currents were related to the electrocatalytic oxidation of acyclovir via the electrogenerated
active species of Cu(III) with an EC’ mechanism. Acyclovir was oxidized with higher rates at low potentials on nano-CPE compared
to micro-CPE. This was related to the nanosize effect of copper nanoparticles. The constants of the electrocatalytic oxidation
process and the diffusion coefficient of acyclovir were reported. A sensitive and time-saving determination procedure was
developed for the analysis of acyclovir and the corresponding analytical parameters were reported. The proposed amperometric
method was applied to the analysis of commercial pharmaceutical products (tablets and topical cream) and the results were
in good agreement with the declared values. 相似文献
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Hossein Heli S. Majdi A. Jabbari N. Sattarahmady A. A. Moosavi-Movahedi 《Journal of Solid State Electrochemistry》2010,14(8):1515-1523
The electrooxidation of dextromethorphan on a composite constructed with carbon nanotube–ionic liquid–carbon microparticles was investigated by cyclic voltammetry in a 100 mM phosphate buffer solution, pH 7.40. In the voltammograms, an irreversible diffusion-controlled anodic peak appeared. The diffusion coefficient of dextromethorphan, the electron-transfer coefficient, and the standard rate constant of the electrooxidation process were found to be 3.45?×?10?6 cm2 s?1, 0.65, and 1.67?×?10?3 cm s?1, respectively. A sensitive and timesaving determination procedure was developed for the analysis of dextromethorphan, and the corresponding analytical parameters were reported. Using this method, dextromethorphan was determined with an LOD and LOQ of 8.81 and 29.36 μM in a linear range of 2.5?×?10?4 to 3.3?×?10?3 M, respectively. The proposed amperometric method was successfully applied to the analysis of commercial pharmaceutical products (syrup and oral drop), and the results were in good agreement with the declared values. 相似文献
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In this paper, the local radial point interpolation meshless method (LRPIM) is used for the analysis of two‐dimensional potential flows, based on a local‐weighted residual method with the Heaviside step function as the weighting function over a local subdomain. Trial functions are constructed using radial basis functions. The present method is a truly meshless method based only on a number of randomly located nodes. Integration over the subdomains requires only a simple integration cell to obtain the solution. No element matrix assembly is required and no special treatment is needed to impose the essential boundary conditions. The novelty of the paper is the use of a local Heaviside weight function in the LRPIM, which does not need local domain integration and integrations only on the boundary of the local domains are needed. Effects of the sizes of local subdomain and interpolation domain on the performance of the present method are investigated. The behavior of shape parameters of multiquadrics has been systematically studied. Two numerical tests in groundwater and fluid flows are presented and compared with closed‐form solutions and finite element method. The results show that the use of a local Heaviside weight function in the LRPIM is highly accurate and possesses no numerical difficulties. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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A new series of amphiphilic β-cyclodextrins were designed and synthesized by grafting peptide chains on to all primary hydroxyl groups via ester bond formation. The desired amphiphilic structures have been produced from ester connection between the C-6 of β-cyclodextrin and the carboxyl group of N-acetylated resides: H2N-Leu-COOH, H2N-Leu-Gly-COOH, H2N-Leu-Gly-Leu-COOH, and H2N-Leu-Gly-Leu-Gly-COOH (3a-d). The synthetic pathway involves selective bromination of all primary hydroxyls of β-cyclodextrins and then substitution with the carboxylate moiety of the mentioned N-acetyl residues in the presence of DBU (1,8-diazabicyclo[5,4,0]undec-7-ene). The ability of the synthetic compounds for extraction and phase transfer of glucosamine, as a hydrophilic organic compound, was then studied. The results showed a considerable ability of these amphiphilic compounds for extraction and a selective tendency of 3c for phase transfer of glucosamine. 相似文献
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A simple and rapid liquid-liquid extraction of palladium has been studied involving ion-pairing of bromocomplexes of palladium(II) with hexadecylpyridinium bromide (HDPB) dissolved in chloroform. The stoichiometry and distribution of (HDP)2PdBr4 between the aqueous and organic phase was investigated by spectrophotometric mole ratio method. The extraction efficiency of palladium(II) by HDPB was studied as a function of several variables: acid, salt, surfactant concentration and equilibrium time. The results showed that PdBr4(2-) extraction could be explained by assuming the formation of (HDP)2PdBr4 complexes in the aqueous solution and transfer to organic phase. The extraction was fast and the shaking time was only a few min. The average recovery of palladium(II) from an aqueous solution containing 10 microg/ml of analyte was 99% with an RSD% of 0.95. The percentage recovery of 0.2 microg/ml palladium(II) was 96%. 相似文献