1,673 research outputs found

    Macromolecular confinement of therapeutic protein in polymeric particles for controlled release: insulin as a case study

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    Sustained release systems for therapeutic proteins have been widely studied targeting to improve the action of these drugs. Molecular entrapping of proteins is particularly challenging due to their conformational instability. We have developed a micro-structured poly-epsilon-caprolactone (PCL) particle system loaded with human insulin using a simple double-emulsion w/o/w method followed by solvent evaporation method. This formulation is comprised by spheric-shaped microparticles with average size of 10 micrometers. In vitro release showed a biphasic behavior such as a rapid release with about 50% of drug delivered within 2 hours and a sustained phase for up to 48 h. The subcutaneous administration of microencapsulated insulin showed a biphasic effect on glycemia in streptozotocin-induced diabetic mice, compatible with short and intermediate-acting behaviors, with first transition peak at about 2 h and the second phase exerting effect for up to 48h after s.c. administration. This study reveals that a simplified double-emulsion system results in biocompatible human-insulin-loaded PCL microparticles that might be used for further development of optimized sustained release formulations of insulin to be used in the restoration of hormonal levels

    Antifungal activity of 7-hydroxycalamenene-rich essential oil nanoemulsion.

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    The aim of this study was to evaluate the inhibitory activity of 7-hydroxycalamenene-rich essential oil nanoemulsion against filamentous fungi and yeasts

    Formulation and optimisation of novel transfersomes for sustained release of local anaesthetic

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    Objective: To investigate the effect of formulation parameters on the preparation of transfersomes as sustained‐release delivery systems for lidocaine and to develop and validate a new high‐performance liquid chromatography (HPLC) method for analysis. Method: Taguchi design of experiment (DOE) was used to optimise lidocaine‐loaded transfersomes in terms of phospholipid, edge activator (EA) and phospholipid : EA ratio. Transfersomes were characterised for size, polydispersity index (PDI), charge and entrapment efficiency (%EE). A HPLC method for lidocaine quantification was optimised and validated using a mobile phase of 30%v/v PBS (0.01 m) : 70%v/v Acetonitrile at a flow rate of 1 ml/min, detected at 255 nm with retention time of 2.84 min. The release of lidocaine from selected samples was assessed in vitro. Key findings: Transfersomes were 200 nm in size, with PDI ~ 0.3. HPLC method was valid for linearity (0.1–2 mg/ml, R2 0.9999), accuracy, intermediate precision and repeatability according to ICH guidelines. The %EE was between 44% and 56% and dependent on the formulation parameters. Taguchi DOE showed the effect of factors was in the rank order : lipid : EA ratio ˃ EA type ˃ lipid type. Optimised transfersomes sustained the release of lidocaine over 24 h. Conclusion: Sustained‐release, lidocaine‐loaded transfersomes were successfully formulated and optimised using a DOE approach, and a new HPLC method for lidocaine analysis was developed and validated

    Self-Nanoemulsifying Drug Delivery System (SNEDDS) Using Lipophilic Extract of Viscum album subsp. austriacum (Wiesb.) Vollm

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    Camila Faria de Amorim Pereira,1,* Michelle Nonato de Oliveira Melo,1,* Vania Emerich Bucco de Campos,2 Ivania Paiva Pereira,1 Adriana Passos Oliveira,1 Mariana Souza Rocha,1 João Vitor da Costa Batista,3,4 Valter Paes de Almeida,5 Irailson Thierry Monchak,5 Eduardo Ricci-Júnior,6 Rafael Garrett,7 Aline Gabrielle Alves Carvalho,7 Jane Manfron,5 Stephan Baumgartner,3,8,9 Carla Holandino1,3 1Multidisciplinary Laboratory of Pharmaceutical Sciences, Faculty of Pharmacy, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; 2Department of Pharmacy, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil; 3Society for Cancer Research, Hiscia Institute, Arlesheim, Switzerland; 4Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland; 5Postgraduate Program in Pharmaceutical Sciences, Universidade Estadual de Ponta Grossa, Ponta Grossa, Paraná, Brazil; 6Galenic Development Laboratory (LADEG), Department of Drugs and Medicines, Faculty of Pharmacy, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; 7Metabolomics Laboratory, Chemistry Institute, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; 8Institute of Integrative Medicine, University of Witten/Herdecke, Herdecke, Germany; 9Institute of Complementary and Integrative Medicine, University of Bern, Bern, Switzerland*These authors contributed equally to this workCorrespondence: Carla Holandino, Multidisciplinary Laboratory of Pharmaceutical Sciences, Universidade Federal do Rio de Janeiro, Faculty of Pharmacy, Block B basement, Room 34, 373, Carlos Chagas Filho Avenue, Cidade Universitária, Rio de Janeiro, RJ, 21941-902, Brazil, Email [email protected] Stephan Baumgartner, Institute of Complementary and Integrative Medicine, University of Bern, Bern, Switzerland, Email [email protected] and Purpose: Natural products are potential sources of anticancer components. Among various species, the lipophilic extract of the Viscum album subsp. austriacum (Wiesb.) Vollm. (VALE) has shown promising therapeutic potential. The present work aimed to qualify the plant source and characterize the extract’s chemical profile. In addition, a self-nanoemulsifying drug delivery system (SNEDDS) containing VALE (SNEDDS-VALE) was developed.Methods: V. album subsp. austriacum histochemistry was performed, and the chemical profile of VALE was analyzed by GC-MS. After the SNEEDS-VALE development, its morphology was visualized by transmission electron microscopy (TEM), while its stability was evaluated by the average droplet size, polydispersity index (PdI) and pH. Lastly, SNEDDS-VALE chemical stability was evaluated by LC-DAD-MS.Results: The histochemical analysis showed the presence of lipophilic compounds in the leaves and stems. The major compound in the VALE was oleanolic acid, followed by lupeol acetate and ursolic acid. SNEDDS was composed of medium chain triglyceride and Kolliphor® RH 40 (PEG-40 hydrogenated castor oil). A homogeneous, isotropic and stable nanoemulsion was obtained, with an average size of 36.87 ± 1.04 nm and PdI of 0.14 ± 0.02, for 14 weeks.Conclusion: This is the first histochemistry analysis of V. album subsp. austriacum growing on Pinus sylvestris L. which provided detailed information regarding its lipophilic compounds. A homogeneous, isotropic and stable SNEDDS-VALE was obtained to improve the low water solubility of VALE. Further, in vitro and in vivo experiments should be performed, in order to evaluate the antitumoral potential of SNEDDS-VALE. Keywords: Viscum album subsp. austriacum, mistletoe, lipophilic extract, oleanolic acid, SNEDD

    Combined search for the quarks of a sequential fourth generation

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    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

    Punica granatum L. protects mice against hexavalent chromium-induced genotoxicity

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    This study investigated the chemoprotective effects of Punica granatum L. (Punicaceae) fruits alcoholic extract (PGE) on mice exposed to hexavalent chromium [Cr(VI)]. Animals were pretreated with PGE (25, 50 or 75 mg/kg/day) for 10 days and subsequently exposed to a sub-lethal dose of Cr(VI) (30 mg/kg). The frequency of micronucleated polychromatic erythrocytes in the bone marrow was investigated and the Cr(VI) levels were measured in the kidneys, liver and plasm. For the survival analysis, mice were previously treated with PGE for 10 days and exposed to a single lethal dose of Cr(VI) (50 mg/kg). Exposure to a sub-lethal dose of Cr(VI) induced a significant increase in the frequency of micronucleated cells. However, the prophylactic treatment with PGE led to a reduction of 44.5% (25 mg/kg), 86.3% (50 mg/kg) and 64.2% (75 mg/kg) in the incidence of micronuclei. In addition, the 50 mg/kg dose of PGE produced a higher chemoprotective effect, since the survival rate was 90%, when compared to that of the non-treated group. In these animals, reduced amounts of chromium were detected in the biological materials, in comparison with the other groups. Taken together, the results demonstrated that PGE exerts a protective effect against Cr(VI)-induced genotoxicity

    Measurement of the triple-differential cross section for photon plus jets production in proton-proton collisions at √s = 7 TeV

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