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61.
AHMED Khan MUHAMMAD Asghar MOHAMMED Yaqoob MASOOD Ahmed Siddiqui SAMAR Ali 《高等学校化学研究》2021,37(3):629-638
Asensitive and selective method employing chemiluminescence(CL) coupled with flow injection(FI) is reported for nalbuphine hydrochloride(NAL) assay in pharmaceutical formulations. The enhancement effect of NAL on the CL reaction between tris(2,2'-bipyridyl)ruthenium(II) chloride-diperiodatocuprate(III) {Ru[(bpy)3]2+-Cu(III) complex} in acidic medium is used as analytical measurement. The optimal conditions of the CL reaction were sulfuric acid 1.0×10-3 mol/L, Ru[(bpy)3]2+ 7.5×10-5 mol/L, Cu(III)/Ag(III) complexes 4.0×10-4/5.0×10-4 mol/L, sample loop volume of 120 μL and flow rate of 2.5 mL/min. The sensitivities of the method in terms of detection(S/N=3) and quantification(S/N=10) limits are 5×10-4 and 0.001 ppm(1 ppm=1 mg/L), respectively. The linear response of the instrument in the form of CL intensity with respect to NAL concentration is over the range 0.001-15.0 ppm(R2=0.9999) with relative standard deviation from 0.8% to 3.2% and injection throughput of 120 injection/h. The applications of the method include the quantitative analysis of NAL in pharmaceutical injection samples. Variations and the average results of the proposed method are not signi-ficantly different from the results of a reported method by applying F- and paired student t-test. The most likely CL reaction mechanism is written in accordance with spectrophotometric and CL studies. 相似文献
62.
Yong Guan Huanyao Zhang Anna Zheng Dafu Wei Jian Hu Zhenzhen Wang Xiang Xu 《先进技术聚合物》2019,30(7):1555-1563
Recently, silicone rubber (VMQ) was extensively used in household articles and medical devices. To develop a kind of safe and long‐term antimicrobial VMQ was of great significance. In this work, a kind of vinyl‐contained polyhexamethylene guanidine hydrochloride (VPHMG) was synthesized and used as antimicrobial additive for VMQ. With the increasing of VPHMG addition, the mechanical properties and antimicrobial properties of VMQ‐VPHMG were significantly improved. In particular, the antimicrobial rates against Escherichia coli and Staphylococcus aureus were higher than 99.99% as for 4 wt% of VPHMG addition. Moreover, the surface concentration of VPHMG as well as the antimicrobial rates revealed almost unchanged after being extracted by water and methanol. All the results indicated the vinyl‐contained VPHMG vulcanization and therefore provided the permanent antimicrobial performance for VMQ. 相似文献
63.
A simple and high‐resolution HPLC‐PDA method for simultaneous quantification of local anesthetics in in vitro buccal permeation enhancement studies
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Renê O. Couto Camila Cubayachi Renata F. V. Lopez Cristiane M. de Gaitani Vinícius Pedrazzi Osvaldo de Freitas 《Biomedical chromatography : BMC》2016,30(6):857-866
A simple, isocratic, high‐resolution and prompt HPLC‐PDA method was developed and validated for the simultaneous quantification of prilocaine (PCL) and lidocaine (LCL) hydrochlorides in in vitro buccal iontophoresis‐driven permeation studies. A reversed‐phase C18 column (250 mm x 4.6 mm, 3μm, 110Å) was used for the chromatographic separation. The mobile phase contained acetonitrile: 0.1M sodium phosphate buffer, pH 7.0 (1:1, v/v), plus 0.05% (v/v) diethylamine. The isocratic flow rate was set at 1 mL/min and the detection wavelength was 203 nm. PCL and LCL eluted in 8.9 min and 13 min, respectively, and the system suitability parameters varied within an acceptable range. The method was selective, sensitive, precise, accurate and robust, producing a linear plot at the concentration range of 0.25 to 10 µg/mL. The application of this method was demonstrated by a significant enhancement of the permeation of PCL and LCL with the application of iontophoresis (1 mA/cm2 per 1 h) through isolated porcine esophageal epithelium. The amount of the drug retained in the epithelium also increased with the application of an electrical current. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
64.
Sonika Asijaa Nidhi Malhotra Rajeh Malhotra 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):1510-1520
Abstract Diorganotin(IV) complexes of an extended system derived from the condensation of pyridoxal hydrochloride with 2-amino phenol (H2L1), 2-amino-4-methyl phenol (H2L2), 2-amino-4-chloro phenol (H2L3), 2-amino-4-nitro phenol (H2L4), 1-amino-2-naphthol hydrochloride (H2L5) have been synthesized by the reaction of dichlorodiorganotin(IV) in a 1:1 molar ratio with these ligands. Spectral studies (IR, 1H, 13C, 119Sn NMR) along with physical data evidenced the formation of penta-coordinated species with the ligands acting as tridentate (ONO) with oxygen occupying the axial positions, and nitrogen at one of the equatorial positions. The ligands and their organotin complexes have been evaluated for antimicrobial activity against phytopathogenic fungi Candida albicans and Aspergillus niger at 25 ± 1 °C and bacteria Bacillus subtilis, Escherichia coli, and Staphylococcus aureus at 37 ± 1 °C. The activities of the ligands have been enhanced on complexation and the results indicate that they exhibit significant antimicrobial properties. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
65.
Marwa F. Mansour Ehab F. El‐Kady Nabawia M. El‐Guindi Samir M. El‐Moghazy Ann Van Schepdael 《Journal of separation science》2013,36(20):3432-3439
A simple CE method was developed and validated for the simultaneous determination of chlordiazepoxide (CHL), amitriptyline, and nortriptyline (mixture I) or the determination of CHL and imipramine (mixture II) using the same BGE. Sertraline and amitriptyline were used as internal standards for the first and second mixtures, respectively. The method allows amitriptyline to be completely separated from its impurity and main metabolite nortriptyline, which can be quantified from 0.2 μg/mL. The separation was achieved using 20 mM potassium phosphate buffer pH 5 containing 12 mM β‐cyclodextrin and 1 mM carboxymethyl‐β‐cyclodextrin. UV detection was performed at 200 nm and a voltage of 15 kV was applied on an uncoated fused‐silica capillary at 25°C. These experimental conditions allowed separation of the compounds to be obtained in 7 min. Calibration graphs proved the linearity up to 40 μg/mL for CHL, up to 100 μg/mL for amitriptyline and imipramine, and up to 5 μg/mL for nortriptyline. The accuracy and precision of the method have been determined by analyzing synthetic mixtures and pharmaceutical formulations. The analytical results were quite good in all cases indicating that the method was linear, sensitive, precise, accurate, and selective for both mixtures. 相似文献
66.
A simple and efficient one-pot synthesis of 1H-benzimidazole derivatives using thiamine hydrochloride (VB1) as the organocatalyst from o-phenylenediamine and aldehyde in dimethylformamide is described. Compared to classical reaction conditions, this new method consistently has the advantages of excellent yields, metal-ion-free procedure, and good recovery and reusablity of catalyst. 相似文献
67.
68.
Primary thioamides are prepared in moderate to excellent yields by treating nitriles with sodium hydrogen sulfide and diethylamine hydrochloride in an appropriate solvent with mild heating. 相似文献
69.
The present work describes the formulation of alginate microspheres containing diltiazem hydrochloride by the emulsification-internal gelation method with the use of barium carbonate as a cross-linking agent. The effect of various factors (the concentration of alginate and barium chloride) on the drug loading efficiency and in vitro release were investigated. Fourier transform infrared microscopy (FTIR) and differential scanninig calorimetry (DSC) analysis confirmed the absence of any drug polymer interaction. X-ray diffraction (XRD) pattern showed that there is a decrease crystallinity of the drug. The in vitro drug release profile could be altered significantly by changing various processing parameters to give a controlled release of drug from microcapsules. The stability studies of drug-loaded microcapsules showed that the drug was stable at different storage conditions. 相似文献
70.
Kabir-ud-Din Malik Abdul Rub Md. Sayem Alam 《Journal of Dispersion Science and Technology》2013,34(9):1182-1187
Herein we report the micellization and clouding behavior of promethazine hydrochloride (PMT) in absence and presence of NaCl/ureas. The critical micelle concentration (CMC) of PMT is measured by conductivity method and the values decrease with increasing the NaCl concentration. With increasing the temperature, the CMC first increases then decreases. At 25°C, the maximum CMC values were obtained (with or without NaCl). The thermodynamic parameters are evaluated which indicate more stability of the PMT solution in presence of NaCl. PMT shows phase separation also. The cloud point (CP) of PMT decreases with increase in pH due to deprotonation of the drug molecules. Ureas decreased the CP and the behavior is explained on the basis of removal of water from the head group region. 相似文献