Recursos de colección

Universidad Nacional de La Plata (74.783 recursos)

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vol. 31, no. 06

Mostrando recursos 1 - 20 de 22

  1. Determination of dezocine in rabbit plasma by liquid chromatography-mass spectrometry and its application

    Zhang, Yuan; Zheng, Yuancai; Chen, Tongke; Zhu, Jiayin; Zhao, Huiling; Lin, Guanyang
    A sensitive and selective liquid chromatography-mass spectrometry (LC–MS) method for determination of dezocine in rabbit plasma was developed and validated. After addition of diazepam as internal standard (IS), liquid–liquid extraction (LLE) was used for sample preparation, and chromatography involved Agilent SB-C18 column (2.1 mmx50 mm, 3.5 um) using 0.1 % formic acid in water and acetonitrile as a mobile phase with gradient elution. Detection involved positive ion mode electrospray ionization (ESI), and selective ion monitoring (SIM) mode was used for quantification of target fragment ions m/z 245.8 for dezocine and m/z 284.8 for diazepam (internal standard, IS). The assay was...

  2. Propofol exhibits inhibitory effect towards human liver microsomes (HLMs)- catalyzed glucuronidation of thienorphine

    Zhang, Shu-Yao; Chen, Lei; Lin, Chao-Xian; Zhu, Zhi-Wei; Fang, Ling; Xin, Dai-Shan; Guo, Dai-Nian
    Drug-drug interaction (DDI) is a challenging problem in the process of drug utilization. Inhibition of glucuronidation reaction of drugs is a major reason for DDI. The aim of the present study is to predict propofol-thienorphine interaction from the perspective of propofol’s inhibition towards thienorphine glucuronidation. The human liver microsomes (HLMs) incubation system supplemented with uridine 5’-diphosphoglucuronic acid (UDPGA) was used. The results showed that propofol inhibited HLMscatalyzed thienorphine glucuronidation in a concentration-dependent manner. Both Dixon plot and Lineweaver-Burk plot showed that the inhibition of thienorphine glucuronidation by propofol was best fit to competitive inhibition, and the second plot using slopes...

  3. A simple HPLC method for the determination of pentyl gallate and identification of an alkaline degradant

    Dias, Daiane O.; Nunes, Ricardo José; Teixeira, Helder; Bassani, Valquiria L.; Simões, Cláudia Maria Oliveira; Koester, Letícia S.; Kelmann, Regina G.
    Pentyl gallate (PG) is a gallic acid n-alkyl ester with a promising antiherpetic topical activity. No method for PG quantification is described in the literature. Therefore, the objective of this investigation is to develop and validate a simple method for determination of PG by High performance liquid chromatography (HPLC) considering its future application in therapy. A nanoemulsion was proposed as PG delivery system due to its low aqueous solubility that limits its delivery through the skin. Chromatographic separation was achieved on a C18 column with 50:49:1 (%, v/v) methanol:water:trifluoroacetic acid (TFA) as mobile phase at a flow rate of 1.2 mL/min;...

  4. Metoprolol-eudragit microcapsules: pharmacokinetic study using convolution approach

    Murtaza, Ghulam; Khaled, Abdulhakim A.A.; Pervaiz, Khalid; Farzana, Kalsoom
    The objective of this study was to employ convolution approach for the calculation of blood drug levels for various release types (1:1, 1:1.5, and 1:2, drug:polymer) of metoprolol tartrate microparticulate formulations from in vitro drug dissolution profiles. Using USP 2007 dissolution apparatus II, dissolution testing was carried out by employing sequential pH change method with and without 0.5 % soudium lauryl sulphate, surfactant. The values of derived pharmacokinetic parameters like Cmax (Maximum blood drug concentration), Tmax (Time needed to reach maximum blood drug concentration), and AUC (area under blood drug concentration curve) from the predicted drug concentration in blood were...

  5. Determination of emodin, chrysophanol, and physcion by HPLC in the chinese medicine rumex japonicus houtt.

    Lin, Chongliang; Chen, Mengchun; Cai, Jinzhang; Lai, Minmin; Zheng, Yiting; Yang, Xuezhi
    A high performance liquid chromatography (HPLC) method for determination of emodin, chrysophanol and physcion in Rumex japonicus Houtt. from different places in Zhejiang Province (China) was established. The samples were separated on a Agilent Zorbax SB-C18 column (2.1 × 150 mm, 5 μm) at at a flow rate of 0.4 mL/min using acetonitrile-water as the mobile phase, with a gradient elution. The column oven temperature was 30 °C and the wavelength of detection used was 285 nm. The three anthraquinones were well separated by this HPLC method. Linearities of emodin, chrysophanol, and physcion were good in the ranges of 0.23-46...

  6. Pharmacokinetics of andrographolide dripping pills, a modern chinese herb medicine, by LC-MS/MS method in beagle dogs

    Chu, Yang; Bai, Xiaolin; Zhang, Shunnan; Li, Wei; Wang, Xiangyang; Guo, Jiahua; Ma, Xiaohui; Zhu, Yonghong
    A rapid and sensitive method for the analysis of andrographolide in dog plasma using liquid chromatography coupled to tandem electrospray ionization mass spectrometry (LC-MS/MS) was developed and validated. The analyte and internal standard (IS), warfarin, were extracted from plasma with ethyl acetate and then separated by RP-HPLC. Detection was performed by negative ion electrospray ionization in multiple reaction monitoring (MRM) mode, monitoring the transitions m/z 349.1→287.2 and m/z 307.0→116.9, for quantification of andrographolide and IS, respectively. Excellent linearity was found to be from 2.5 to 1000 ng/mL with a lowest limit of quantitation (LLOQ) of 2.5 ng/mL. The inter-day accuracy...

  7. Interaction of antihypertensive drugs with atorvastatin in hyperlipidemic cardiac patients

    Sohail, Muhammad; Janbaz, Khalid H.; Ahmad, Saeed; Abbas, Tariq
    The present study was undertaken to reveal the possible influence of atenolol, amlodipine and amlodipine plus lisinopril upon lipid lowering profile of atorvastatin in cardiac patients with hyperlipidemia and hyperlipidemia plus hypertension attending a tertiary care cardiology hospital. Selected patients were divided into four groups. Group A (n = 9) declared as control and the patients in this group received oral dose of atorvastatin (20 mg/day) without antihypertensive medication, group B (n = 9) patients received atorvastatin (20 mg/day) along with atenolol (50-100 mg/day) as antihypertensive agent. Whereas group C patients (n = 9) being recipients of atorvastatin (20 mg/day)...

  8. Simultaneous determination of four cytochrome p450 probe drugs in rat plasma by a simple liquid chromatography–mass spectrometry method

    Hu, Lufeng; Xu, Ren-ai; Wang, Zhe; Ma, Jianshe; Pan, Jianchun; Wang, Xianqin
    A sensitive and simple liquid chromatography- mass spectrometry (LC-MS) method was developed and validated for determination of four cytochrome P450 probe drugs (phenacetin (CYP1A2), tolbutamide (CYP2C9), bupropion (CYP2B6) and omeprazole (CYP2C19) in rat plasma. Four cytochrome P450 probe drugs extracted from plasma samples by protein precipitation with acetonitrile and separation were carried out on Agilent Zorbax SB-C18 column (2.1 mm x 150 mm, 5 μm) at 30 °C, acetonitrile –0.1 % formic acid in water used as mobile phase with gradient elution. Electrospray ionization (ESI) source was applied and operated in positive ion mode, and selective ion monitoring (SIM) mode...

  9. Determination of free cyclosporine A with a LC-MS/MS method: Application to C2 monitoring in rabbits

    Xu, Ren-ai; Zhang, Chunhong; Pan, Xiaofeng; Shi, Da-wei; Hu, Lufeng; Ye, Xiao-lan; Liu, Yun-jie; Zhang, Xiuhua
    Cyclosporine A (CsA) is a cyclic peptide widely used as an immunosuppressant. Therapeutic drug monitoring (TDM) of CsA is becoming mandatory for transplant patients who received CsA therapy in the routine clinical practice because of large individual variability, dose-related toxicity and the risk of acute rejection. In this study, a rapid, sensitive, and selective LC-MS/MS method was developed and validated for the quantitative analysis of free CsA (fCsA), a better indicator for the prediction of efficacy and safety of CsA-based therapy. Following ultrafiltration for fCsA, chromatographic separation was performed on an Agilent Zorbax SB-C18 column (100 mm x 2.1 mm,...

  10. In vitro performance of fluticasone/salmeterol pressurized metered dose inhaler in combination with three different valved holding chambers

    Gonçalves, Talita M.; Rizzo, José Â.; Dubus, Jean-Christophe; Nicolay, Alain; Santana, Davi P.; Souza, Pedro H. N. de; Figueiroa, José N.; Andrieu, Veronique
    Spacer devices are used to optimize airway aerosol deposition from pressurized metered-dose inhalers (pMDI). The in vitro performance of the combination fluticasone/salmeterol pMDI alone and connected to 3 different valved holding chambers (VHC) was compared by measuring impactor entry port (“throat”) deposition and fine particle dose (FPD) of each medication. Salmeterol (SX) and Fluticasone (FP) throat deposition was reduced over 90 % by all VHC compared to pMDI alone (p < 0,001). The FPD obtained from pMDI alone and connected to VHCs Vortex®, AeroChamber Plus® and Able Spacer® for Salmeterol (25 μg nominal dose) were 12.2 ± 0.7, 12.5 ±...

  11. Perceptions of depressed patients on depressive disorder and antidepressant treatment: elements for the clarification of pharmaceutical care

    Marques, Luciene A.M.; Galduróz, José C. F.; Noto, Ana R.
    The objective was to investigate the perceptions of those with depression regarding their condition and treatment and discuss these findings in the light of the pharmacist’s role in mental health. The study was based on mixed methods, qualitative and quantitative, within the public health network, in 2 health care units of different cities between April 2010 and August 2011; 89 female patients were selected, and 68 agreed to participate in the study. Most women reported feelings of loneliness, abandonment and discouragement, and they think their problems with personal relationships cause depression. They also affirmed that they had little information about...

  12. Adsorption studies of non-ionic surfactants at different vegetable oil-water interfaces

    Hameed, Rao A.; Rabbani, Mehboob-e; Shah, Syed; Khan, Shujaat A.; Yameen, Muhammad A.; Asad, Muhammad H.H.B.; Murtaza, Ghulam
    The adsorption studies of non-ionic surfactants (tween 20, tween 40 and tween 80) were conducted at olive oil-water, sunflower oil-water and corn oil-water interfaces by ring detachment method with a du Nouy Tensiometer at 20 °C. A decrease in interfacial tension with an increase in surfactant concentration was observed at all the oil-water interfaces under investigation. Surface excess was calculated from Gibb’s equation while area per molecule was computed from surface excess. Surface pressure-area curves were plotted to study the states of films formed. On close examination of π-A graphs, it was indicated that all the graphs have three distinct...

  13. Determination of bupropion and hydroxybupropion by LC-MS/MS in rat and its application to assessment of CYP2B6 activity

    Pan, Xiaofeng; Xu, Zhisheng; Du, Xiaoxiang; Hu, Hufeng; Fei, Ai-li; Wang, Zhe; Xu, Ren-ai
    A selective and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for quantitation of bupropion (BUP) and its metabolite hydroxybupropion (HBUP) in rat plasma and urine using carbamazepine as an internal standard. Chromatographic separation was achieved on a SB-C18 column at 30 °C, using the gradient elution of 0.1 % formic acid in water and acetonitrile. Calibration plots were linear over range of 10-2000 ng/mL for BUP and 5-1000 ng/mL for HBUP in rat plasma. The intra- and inter-run relative standard deviations of the assay were less than 10 % for both BUP and HBUP. The effects of...

  14. Preparation and quality evaluation of Ibuprofen and Piphenhydramine hydrochloride orally disintegrating tablets

    Luo, Y.H.; Ge, Z. K.; Zhao, X.Y.; Chen, Q.; Bourkaib, Nadia; Luo, M.; Luo, L.Y.; Wu, Lei; Hu, B. X.
    The present study was designed to evaluate the preparation and quality of ibuprofen and diphenhydramine hydrochloride orally disintegrating tablets. The formulation was optimized with disintegration time and taste as reference parameters by single-factor and orthogonal experiments. Then the hardness, disintegrating time and dissolution were examined. The best prescription was found to contain: ibuprofen 200 mg, diphenhydramine HCl 25 mg, citric acid 30 mg, microcrystalline cellulose 115 mg, mannitol 48.5 mg, polyvinylpolypyrrolidone 40 mg, sodium lauryl sulphate 10 mg, magnesium Stearate 3.5 mg, gum arabic 1.5 mg, aspartame 15 mg, steviosin 1.5 mg, and sodium bicarbonate 10 mg. The orally disintegrating tablets...

  15. Pharmacokinetics, tissue distribution and excretion of Vitexin in mice

    Wang, Yun-jiao; Qu, Gong-lin; Zhang, Wen-jie; Xue, He-fei; Chen, Ying-hui; Yin, Jing-jing; Lu, Dong-rui; Ying, Xi-xiang
    Pharmacokinetics, tissue distribution and excretion of vitexin (VIT) were studied after intravenous and oral administration to mice at dose of 10 mg/kg and 30 mg/kg, respectively. A sensitive and specific HPLC method with internal standard was developed and validated for the pharmacokinetic studies of VIT. The results showed that VIT was rapidly and widespreadly distributed throughout the whole body after administration and the oral bioavailability of VIT was 3.91 %. The highest VIT level after intravenous dose was obtained in gallbladder, followed by lung, liver and kidney. While, the highest VIT level after oral dose was observed in gallbladder, followed...

  16. Pharmacological evaluation of two liposomal doxorubicin formulations

    Medina, Luis A.; Martínez Acevedo, Lizbeth; Juárez Osornio, Carlos; García López, Patricia; Pérez Rojas, Jazmín; Jurado, Rafael; Vázquez Becerra, Héctor
    Two liposomal formulations of doxorubicin (Caelyx® and Doxopeg®) were evaluated for phospholipid content, doxorubicin concentration, liposomal size, zeta potential, osmolarity, phospholipid peroxidation, in vitro release of the drug, pharmacokinetic profile, and cytotoxicity in cancer cell cultures. Phospholipid concentration was not statistically different between formulations. Doxorubicin concentration was in the range of 2.0 mg/mL. Size and zeta potential were in the order of 80 nm and -37 mV, respectively. Osmolarity and peroxidation in both formulations was similar and the in vitro drug release assay indicated minimal release (2 %) of the doxorubicin content after 48 h. Pharmacokinetics parameters in both formulations were...

  17. Chemical and biological study of essential oils from Eugenia pruniformis cambess., an endemic species from Brazilian Atlantic Forest

    Albuquerque, Ricardo D.D.G.; Tietbohl, Luis A. C.; Fernandes, Caio P.; Couteiro, Pedro P.; Eiriz, Débora N.; Santos, Marcelo G.; Silva Filho, Moacélio V.; Alves, Gutemberg G.; Bachinski, Róber; Rocha, Leandro
    Eugenia pruniformis Cambess. is an endemic species from Brazilian Atlantic Forest. Essential oils from leaves and fruits from this species were obtained by hydrodistillation and analyzed by GCMS/CG-FID. In all, 25 compounds were identified, with predominance of sesquiterpene hydrocarbons in both plant parts. The major compounds were β-caryophyllene, bicyclogermacrene, germacrene D, δ- cadinene and α-copaene. Antioxidant activity was performed for essential oil from leaves using ORAC method, showing value of 0.30 ± 0.06 mmol TE/g. Anticholinesterasic evaluation was also performed for this oil, indicating that it inhibited acetylcholinesterase, showing an IC50 of 1798 μg/mL. These results indicate that this essential oil...

  18. Mucoadhesive in situ gel formulations of miconazole nitrate for the treatment of mucosal candidiasis

    Karavana, Sinem Y.; Senyi?it, Zeynep A.; Hilmioglu Polat, Süleyha; Metin, Dilek Y.; Zekioglu, Osman; Baloglu, Esra
    This study focused on developing in situ gel formulations of miconazole nitrate with poloxamer 188 and 407 for treatment of mucosal candidiasis. In situ gel formulations were prepared and gelation temperature, rheological, mechanical and mucoadhesive properties, syringeability and release profiles were evaluated. Based on their suitable gelation temperature properties, formulations containing the poloxamer (Plx) 407 and 188 in ratios of 15:15 (F1), 15:20 (F2) and 20:10 (F3) were chosen for further studies. F3 exhibited typical gel-type mechanical spectra at 37 °C whereas F1 and F2 behaved like weakly cross-linked gels. Texture profile analysis demonstrated that F3 showed the highest cohesiveness,...

  19. Effect of crosslinking with Ca++ and Zn++ in the formation of gellan gum gels

    Verma, Anurag; Pandit, Jayant K.; Wahi, Arun K.
    This study involves an investigation of the effects of crosslinking of gellan gum (GG) with Ca++ or Zn++ on the physical properties of GG gels. GG gels crosslinked with different concentrations of Ca++ or Zn++ were prepared and parameters such as % water holding capacity and penetration thickness were investigated as measures of the extent of interaction of Ca++ or Zn++ with GG molecules. Data generated from the above studies revealed that Zn++ interacted with the GG molecules to a greater extent than Ca++ . In order to further strengthen our finding, we have prepared Zn++ crosslinked and Ca++ crosslinked...

  20. Encapsulation of olanzapine into beeswax microspheres: preparation, characterization and release kinetics

    Manjunath, M.; Aravindram, A. S.; Vishwanathan, B.; Ahmed, Faruqui M.; Gowda, D. Vishakant; Khan, Mohammed S.
    The objective of the present study was to minimise the unwanted side effects of olanzapine (OZ) drug by kinetic control of drug release by entrapping into gastro resistant, biodegradable waxes such as beeswax (BW) microspheres using meltable emulsified dispersion cooling induced solidification technique utilizing a wetting agent. Solid, discrete, reproducible free flowing microspheres were obtained. The yield of the microspheres was up to 94.0 %. The microspheres had smooth surfaces, with free flowing and good packing properties, indicating that the obtained angle of repose, % Carr’s index and tapped density values were well within the limit. More than 97.0 %...

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