Recursos de colección

Universidad Nacional de La Plata (74.538 recursos)

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vol. 30, no. 06

Mostrando recursos 1 - 20 de 32

  1. Metformin reactivity with biuret: application to tablets

    Chahin, Cecilia L.; Delfino, Mario R.; Sarno, María del C.
    A spectrophotometric method was developed for the analysis of metformin, based on its reaction with the biuret reagent. A complex with λmax = 495 nm and stoichiometry 2:1 (metformin-Cu) is generated wich allows the quantification of metformin in tablets. Physicochemical parameters of the product were determined. Sample conditioning by centrifugation was necessary to separate insoluble excipients. Polyvinylpyrrolidone (PVP) was isolated by a solid-liquid extraction with SPE-SCX resin in order to eliminate its interference on the absorbance of the complex. The proposed method was found to be highly precise, having a relative standard deviation, CV % = 0.68. Using this approach...

  2. Macro and microscopic analysis of the leaf and stem of Randia armata (Sw.) DC., Rubiaceae

    Erbano, Marianna; Duarte, Márcia do Rocio
    Randia armata (Sw.) DC., Rubiaceae is a shrub or small tree known as limoeiro-do-mato in Portuguese and widely distributed in Brazil. The vegetative parts are used as wound healing and anti-inflammatory in folk medicine. Due to the interest in expanding the knowledge on this species, this work has investigated the macro and microscopic characters of the leaf and stem, in order to contribute to the quality control analysis in pharmacognosy. Mature leaves and young stems were collected at the Embrapa (Colombo-PR), fixed in FAA, sectioned either by free hand or microtome, and examined in light microscopy. Microchemical tests and scanning...

  3. Comparative bioavailability of two digoxin formulations: determination in human plasma by microparticle enzyme immunoassay

    Junior, Eduardo A.; Duarte, Luciana F.; Vanunci, Moisés L. P.; Silva, Lara C.; Pereira, Renata; Calafatti, Silvana; Junior, José P.
    The present study was performed to compare the bioavailability of two digoxin 0.25 mg tablet formulation in 30 volunteers of both sexes. The study was conducted open with randomized two period crossover design and a three-week washout period. Plasma samples were obtained over a 144 h interval. Digoxin concentrations were analyzed by a validated microparticle enzyme immunoassay with optical detection by fluorescence. Bioequivalence between the products was determined by calculating 90 % confidence intervals (90 % I.C) for the ratio of AUC0-72h and Cmax values for the test and reference products, using logarithmic transformed data. The 90 % confidence intervals...

  4. Clinical study of a multivitamin and polymineral complex associated with Panax ginseng extract (Natus Gerin®)

    Perazzo, Fábio F.; Souza, Gustavo H. B.; Maistro, Edson L.; Rodrigues, Marcelo; Fonseca, Fernando L. A.; Carvalho, José C. T.
    This study aimed to stablish the efficacy of a multivitamin and polyminerals supplemented with Panax ginseng extract (Natus Gerin®) on patients subjected to common physical or mental stress. Patients were randomly divided in two groups and underwent a thorough clinical examination. Group A received Natus Gerin® capsules and B placebo capsules. Two capsules were taken daily during meals during four weeks. Mood and physical activity were evaluated through a questionnaire assessing quality of life. From the 176 patients enrolled, 17 were excluded due to voluntary withdrawal, 81 completed the study in group A and 78 in group B. The treatment...

  5. Antihistaminic activity of Ricinus communis roots using clonidine induced catalepsy in mice

    Taur, Dnyaneshwar J.; Patil, Ravindra Y.
    Clonidine, an α2 adrenoreceptor agonist, induces dose dependent catalepsy in mice, which releases histamine from mast cells which is responsible for different asthmatic conditions. Ricinus communis Linn (Euphorbiaceae) is a medicinal plant; root is sweetish and has been used traditionally in the treatment of inflammation, pain fever, asthma, bronchititis and leprosy. In present study ethanol extract of R. communis roots (ERCR) at doses 100, 125 and 150 mg/kg intraperitoneally was evaluated for antihistaminic activity using clonidine induced catalepsy in mice. Finding of investigation showed that chlorpheniramine maleate and ERCR inhibit clonidine induced catalepsy significantly P < 0.001 when compare to...

  6. Study on pharmacokinetics of Amygdalin after oral administration of semen persicae extraction in rat plasma by HPLC

    Zhang, Zhidan; Gao, Wenyuan; Ma, Chaoyi; Liu, Changxiao
    Semen Persicae was a traditional Chinese medicine for the treatment of diseases such as inflammation and hyperlipemia. Amygdalin was one of the main active ingredients of this traditional Chinese medicine. In this paper, pharmacokinetic study was conducted to obtain pharmacokinetic parameters of amygadalin after oral administration of Semen Persicae extraction in rat plasma. HPLC-UV was used to determine the concentration of amygdalin in rat plasma at different time points after administration. The main pharmacokinetic parameters of amygdalin in rat were obtained based on the analysis of the plasma sample. The pharmacokinetics of amygdalin was fitted with a one-compartment model and...

  7. Quantitative determination of sulphamethoxazole and trimethoprim in powder mixtures using raman spectroscopy and PLS

    Silva, Fabiana E. B. da; Ziech, Cristiane; Dias, Yara P.; Moreira, Eduardo C.; Flores, Érico M. M.; Ferrão, Marco F.
    Raman spectroscopy in combination with partial least-squares (PLS) regression method was developed for sulphamethoxazole (SMZ) and trimethoprim (TMP) simultaneous determination in powder mixtures. The calibration set was designed with 18 samples and validation set with 9 samples, containing different SMZ and TMP concentrations. The concentration ranges were 400-900 mg/g for SMZ and 80- 240 mg/g for TMP. The proposed procedure was validated by comparison with the official method (HPLC). Mean root square error of calibration (RMSEC) and mean root square error of prediction (RMSEP) were calculated. RMSEC found was 30.96 mg/g to SMZ and 14.36 mg/g to TMP, respectively. RMSEP...

  8. Compatibility studies of Olanzapine pre-formulated with excipients by thermal analysis: preliminary study

    Marques, Lucas M. M.; Medeiros, Maria G. F. de; Nunes, Lívio C. C.; Citó, Antônia M.G.L.; Lopes, José A. D.; Souza, Alexandre A.; Souza, Claide M. L.
    Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to investigate drug-excipient interactions and, in consequence, their compatibility. For this purpose, binary mixtures of olanzapine drug substance and the excipients croscarmellose sodium, magnesium stearate and microcrystalline cellulose, were prepared and analysed. By the analysis of the binary mixtures DSC and TG curves it were observed changes on the temperature and enthalpy values of the drug melting and decomposition peak, with the likely formation of intermediate substances.

  9. In vitro study on anthelmintic activity of Aristolochia indica and A. tagala roots

    D'Souza, Marina G.; Bheemappa, Eswarappa; Pai, Vasantakumar K.; Byahatti, Vivek V.; Tule, Chandramouli
    The present study has been undertaken to screen the anthelmintic potential of aqueous root extracts of Aristolochia indica Linn. and A. tagala Cham. against adult Indian earthworm Pheritima posthuma and round worms Ascaridia galli. Different concentrations of the extracts ranging from 2-8 mg/mL were screened. Piperazine citrate was used as reference standard. Extract of A. tagala was found to be more potent and effective at the dose level of 2 mg/mL compared to the extract of A. indica. Extracts showed dose dependant activity. The study reports that the plants A. indica and A. tagala roots possess potent anthelmintic properties.

  10. Development and evaluation of carvedilol/ polyethylene oxide matrix tablets

    Barboza, Fernanda M.; Stulzer, Hellen Karine
    Hydrophilic matrix tablets were developed with carvedilol (CRV), using different molecular weights of polyethylene oxide (PEO). Investigations were carried out in order to verify the tablets performance. All formulations satisfied the official requirements. Water uptake studies were influenced by pH value and polymer concentration. CRV release was sustained for 23 and 19 h, in acid and neutral conditions, respectively. The mechanism involved in drug release was characterized by anomalous behavior for all formulations in phosphate buffer whereas in acid conditions they presented a Fickian kinetics, Case II transport and Super Case II transport kinetics for different formulations.

  11. Physicochemical characterization for quality control of Equisetum giganteum L.

    Francescato, Leandro N.; Quinteros, Dayane A.; Loreto Bordignon, Sergio Augusto de; Bassani, Valquiria L.; Henriques, Amélia T.
    This work presents physicochemical and chemical characterization of Equisetum giganteum L. stems, an endemic species of Latin America widely used in the traditional medicine, mainly as diuretic. The loss on drying, total ash and acid-insoluble ash values were 11.85 ± 0.11 %, ≥13.61 ± 0.38 %, and ≥ 9.43 ± 0.35 %, respectively. The total phenolic and flavonoid content were 7.27 ± 0.05 mg GAE/g and 0.42 ± 0.0141 g %, respectively. Data on drying, adsorption and sorption isotherms and other physicochemical determinations are also presented. Thin layer and liquid chromatography profiles revealed the presence of polyphenols. These results will...

  12. Preparation and characterization of gellan-chitosan polyelectrolyte complex beads

    Dixit, Raghav; Verma, Anurag; Soni, Shashank; Mishra, Arun K.; Bansal, Ashok K.; Pandit, Jayant K.
    The purpose of the present investigation was to prepare gellan-chitosan polyelectrolyte complex beads in one step and to explore the potential of the prepared beads in the oral delivery of metronidazole (log P = 0.0) and metronidazole benzoate (log P = 2.19). Beads were prepared by extruding aqueous solution of gellan gum (with or without drugs) into chitosan solution in acetic acid pH adjusted to 3.5. Prepared beads exhibited poor encapsulation and burst release for metronidazole, while very high encapsulation and extended release was observed for metronidazole benzoate in simulated gastric fluid (SGF, pH 1.2). Incorporation of type A &...

  13. Studies on in-vitro transcutaneous delivery of losartan potassium, influence of penetration enhancers and barrier membrane

    Petkar, Kailash C.; Pore, Yogesh V.; Kuchekar, Bhanudas S.
    Formulation and in vitro evaluation of losartan potassium (LP) loaded transdermal delivery system (TDS) was investigated for controlled release and improved therapeutic efficacy. TDS (patches) were prepared by varying the composition of Eudragit RL 100 and Eudragit RS 100 (5:0, 4:1, 3:2, 2.5:2.5, 2:3, 1:4 and 0:5). Patches were evaluated for thickness, content uniformity, mechanical properties, moisture uptake and in vitro drug release. Technological parameters for all the formulations were found to be within the limit. In vitro studies showed relatively high permeation of LP (F1- 42.17 ± 1.13 %) from the formulation comprising 4:1 ratio of polymer. Inclusion of...

  14. Evolution of adherence to antiretroviral treatment in a spanish hospital during 2001, 2005 and 2008

    Echarri Martínez, Lara; Rodríguez González, Carmen G.; Castillo Romera, Isabel; Trovato López, Nicolás; Ais Larisgoitia, Arantza; Bellón Cano, José M.; Sanjurjo Sáez, María
    The aim of this study was to analyze the evolution of adherence to highly active antiretroviral therapy (HAART) in the Hospital General Universitario Gregorio Marañón (Madrid, Spain) over the last 8 years and determine the variables associated with the complexity of treatment and suboptimal adherence. An observational, retrospective method was used to measure adherence during the first 6 months of HAART in 3 cohorts: 2001 cohort (n = 90), 2005 cohort (n = 98), and 2008 cohort (n = 110). The adherence rate was determined using 2 methods: Pharmacy Department dispensation records and virologic response data. The evolution of the...

  15. Simultaneous determination of prodrug of Ginkgolide B and Ginkgolide B in rat plasma by LC-MS/MS

    Pan, Jian; Wu, Zeyu; Yuan, Yuan; Hui, Ailing; Yang, Yi
    A simple and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was established and validated for the determination of prodrug of ginkgolide B (PGB) and its metabolite, ginkgolide B (GB) in rat plasma. The separation was achieved on a Waters Symmetry Shield RP18 column (150 mm × 3.9 mm i.d., 5 μm particle size), using a mobile phase composed of methanol/water with 10 mM ammonium acetate (85:15, v/v) at a flow rate of 800 μL/min in 2 min. An API 3200 triple quadrupole mass spectrometer equipped with electrospray ionization source was operated in negative ionization mode. Multiple reaction monitoring (MRM)...

  16. Spectrophotometric determination of captopril through charge transfer complex formation using fractional factorial and central composite design

    Ribeiro, Paulo R. S..; Pezza, Leonardo; Pezza, Helena; Tognolli, João O.
    A new spectrophotometric method was developed for the determination of captopril (n donor) through charge transfer complex formation with p-chloranil (π acceptor). The different experimental parameters that affect the absorbance intensity were carefully studied. Thus, these parameters were optimized using chemometric methods of fractional factorial and central composite design. At the optimum reaction conditions, the rectilinear calibration graphs were obtained in the concentration range 1.86 x 10-4 to 7.38 x 10-4 mol/L captopril with an excellent correlation coefficient (r = 0.9996). The proposed procedure could be applied successfully for the determination of the investigated drug in their pharmaceutical dosage forms...

  17. Comparative study on the pharmacokinetic of lansoprazole in gastric ulcer and normal rabbits by HPLC-DAD

    Jiang, Xianglan; Wu, Jing; Tang, Daoquan; Gao, Yuanyuan; Yang, Dongzhi; Zhao, Ziming; Chen, Hui
    Gastric ulcer is one of ulcerous diseases and may result in some changes of many enzymes and transporters concerned with metabolism and disposal of drug. The pharmacokinetic of drug should be different between peptic ulcer and normal animals. Lansoprazole has been one of important medicine for treatment of ulcerous diseases. So, this paper investigated the difference of pharmacokinetic profiles of lansoprazole in gastric ulcer and normal rabbits in vivo by HPLC-DAD method. In this work, a liquid-liquid extraction and enrichment method with RP-HPLC determination route was taken. The pharmacokinetic parameters were analyzed by double-compartmental method (DAS2.0). The pharmacokinetic parameters of...

  18. Formulation development of oral timed-release press-coated tablets: optimization and in vivo studies

    Narendra, Chikkanna; Srinath, Mayasandra S.
    The objective of the present study was to develop an oral timed-released press-coated tablet containing theophylline as a model drug. A D-optimal design of experiment was employed to systematically study the effect of ternary blend of ethylcellulose (X1), hydroxypropylcellulose (X2), and Mg stearate (X3) as independent variables. The design was quantitatively evaluated by quadratic model and the results from the statistical analysis revealed that interaction factors X1X2 and X2X3 were found to be highly significant on the studied response variables; percent drug release at 8 h (Y1), percent drug release at 10 h (Y2) and lag time (Y3). A numerical...

  19. Fast disintegrating tablets of flurbiprofen: formulation and characterization

    Vemula, Sateesh K.; Veerareddy, Prabhakar Reddy
    The purpose of development oral fast disintegrating drug delivery is not only to give fast relief but also to overcome difficulty in swallowing tablets and capsules, resulting in non-compliance and ineffective therapy. The aim of present study is to formulate fast disintegrating of flurbiprofen by using superdisintegrants. Flurbiprofen fast disintegrating tablets were prepared by using direct compression method and were characterized for both pre-compression parameters and post-compression parameters to comply with pharmacopoeial limits. From the in vitro drug release studies the optimized formulation showed almost complete drug release (above 99 %) within 15 min. DSC and FTIR studies were carried...

  20. Antimicrobial, antioxidant, and cytotoxic activities of Bixa orellana Linn

    Ul Islam, S.M. Bakhtiar; Hossain, Khalid; Gomes, Isidore; Gomes, Donald J.; Rahman, Sabita Rezwana; Rahman, Mohammad S.; Rashid, Mohammad A.
    Bixa orellana Linn., commonly known as "lipstick plant", is used in folk medicines to treat infections of microbial origin as well as coloring agents in food stuffs in the LDCs like Bangladesh. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the warm water extract of leaves of B. orellana were evaluated against 25 multidrug resistant (MDR) clinical isolates and 6 food-borne pathogens using the micro-dilution broth method modified to comply with the NCCLS standards. The total phenolic content and antioxidant capacity of warm water, ethanol, and methanol extracts of the seeds and leaves of B. orellana were...

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