Albendazole Solid Dispersions: Influence of Dissolution Medium Composition on In Vitro Drug Release

The rate-limiting step to drug absorption is often dissolution from the dosage form, especially for poorly soluble com-pounds. Two possibilities for improving the dissolution of these drugs are to increase the available surface area and to im-prove their apparent solubilities under physiologically relevant conditions with surfactants as wetting agents. Albendazole (ABZ), one of the most effective broad-spectrum antihelminthic agents, has a very low aqueous solubility, which leads to an erratic availability. Solid dispersions (SD) with different amounts of carriers (P188 and PEG6000) were formulated to improve the ABZ dissolution rate. When the dissolution test is used to infer biopharmaceutical properties of the dosage form, it is es-sential that the method simulates the gastrointestinal conditions. The objective of this study was to examine the applicabil-ity of different dissolution media to the evaluation of ABZ and ABZ-SD dissolution rates. Dissolution profiles were performed by the official method (0.1 N HCl) and Simulated Gastric Fluid modified with a surfactant. Wetting was evaluated through the determination of surface tension and contact angle of the solutions. The dissolution rate of ABZ was clearly affected by the variables assessed in this study. These results have implications in the design of physiologically based dissolution media.Fil: González Vidal, Noelia Luján. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Cátedra de Control de Calidad de Medicamentos; ArgentinaFil: Castro, Silvina Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Sanchez Bruni, Sergio Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatología. Laboratorio de Farmacología; ArgentinaFil: Allemandi, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Palma, Santiago Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; Argentin

Valorization of glycerol through the enzymatic synthesis of acylglycerides with high nutritional value

The production of specific acylglycerides from the selective esterification of glycerol is an attractive alternative for the valorization of this by-product of the biodiesel industry. In this way, products with high added value are generated, increasing the profitability of the overall process and reducing an associated environmental threat. In this work, nutritional and medically interesting glycerides were obtained by enzymatic esterification through a two-stage process. In the first stage, 1,3-dicaprin was obtained by the regioselective esterification of glycerol and capric acid mediated by the commercial biocatalyst Lipozyme RM IM. Under optimal reaction conditions, 73% conversion of fatty acids and 76% selectivity to 1,3-dicaprin was achieved. A new model to explain the participation of lipase in the acyl migration reaction is presented. It evaluates the conditions in the microenvironment of the active site of the enzyme during the formation of the tetrahedral intermediate. In the second stage, the esterification of the sn-2 position of 1,3-dicaprin with palmitic acid was performed using the lipase from Burkholderia cepacia immobilized on chitosan as the biocatalyst. A biocatalyst containing 3 wt % of lipase showed good activity to esterify the sn-2 position of 1,3-dicaprin. A mixture of acylglycerides consisting mainly of capric acid esterified at sn-1 and sn-3, and of palmitic acid at the sn-2 position was obtained as the reaction product. The influence of the biocatalyst mass, the reaction temperature, and the molar ratio of substrates were evaluated for this reaction using a factorial design. Simple models were used to adjust the consumption of reagents and the generation of different products. The reaction product contained between 76% and 90% of acylglycerides with high nutritional value, depending on the reaction conditions.Fil: Sanchez, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Tonetto, Gabriela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Ferreira, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Química; Argentin

Synthesis of acylglycerides with high nutritional value by an enzymatic two step process

Acylglycerides are esters formed from glycerol and fatty acids. The structure of these glycerides affects their digestion and absorption. In this work, the synthesis of acylglycerides with high nutritional value by an enzymatic process in two stages is presented. In the first stage, the esterification ofglycerol and capric acid catalyzed by Lipozyme RM IM was carried out. In this reaction, 73% conversion of capric acid and 71% selectivity to 1,3-dicaprinwas achieved. The diglyceride was separated and purified efficiently by a simple liquid-liquid extraction procedure. The dicaprin was esterified with palmiticacid using Burkholderia cepacia lipase immobilized on chitosan as the catalyst. In this second stage, conversions of 1,3-dicaprin with values between 48 and87% and with high selectivity towards the esterification of the sn-2 position were achieved. The reaction product had between 76 and 90% of acylglycerides with high nutritional value, depending on the reaction conditions.Fil: Sanchez, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Tonetto, Gabriela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Ferreira, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; Argentin

Ferromagnetic and multiferroic interfaces in granular perovskite composite xLa0.5Sr0.5CoO3-(1-x)BiFeO3

of ferromagnetic La0.5Sr0.5CoO3 (LSCO) and multiferroic BiFeO3 (BFO) were synthesized by spray pyrolysis method. Different compositions of multiferroic xLSCO-(1-x)BFO composites were synthesized at 800 °C for 2 h. Scanning electron microscopy and energy dispersive spectroscopy elemental mapping were performed to study the morphology of composites. Ferri/ferromagnetic responses above TC (LSCO) are observed, which are associated with the interfaces LSCO/BFO. This interface presents a different behavior compared to the original perovskites, and the magnitude of the magnetization depends on x. Electrical DC conductivity as a function of temperature for LSCO nanopowder (x = 1) presents a different behavior than that reported in bulk material. For x = 1 and 0.9, the model by Glazman and Matveev [Zh. Eksp. Teor. Fiz. 94, 332 (1988)] is proposed to describe the electrical conductivity. On the other hand, x = 0, 0.1, and 0.5 present a variable range hopping behavior. Complex impedance spectroscopy as a function of frequency indicates a pure resistive behavior for x ≥ 0.5 compositions, while a complex resistive-capacitive behavior is observed for low x values (0, 0.1). In these samples, low values of magnetoelectric coupling were measured with an AC lock-in technique.Fil: Lohr, Javier Hernán. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Lopez, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Saleta, Martin Eduardo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Sanchez, Rodolfo Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Natural observatories for lightning research in Colombia

This paper presents a selected, not exhaustive, description of lightning research in Colombia over time, based on natural observatories for experimentation and measurement; and introduces the DABEIBA Lightning Research Center as a new institutional cooperation to concentrate several instruments such as Lightning Mapping Array - LMA, high speed cameras, high energy detectors, by different scientific parties in a single area for tropical lightning research. © 2018 IEEE.Peer ReviewedPostprint (published version

First data of the Colombia Lightning Mapping Array - COLMA

The first data set of VHF lightning mapping using a Lightning Mapping Array system - LMA in a tropical region is presented in this paper. Six sensors were installed at the north of Colombia near Santa Marta city. Since the installation of the LMA network in 2015, up to 7000 intra-cloud (IC) discharges from September to November 2015 have been analyzed. The data suggests that, the electrical charge distribution in tropical thunderstorms shows higher vertical development reaching higher altitudesPreprin

Reliability of Running Stability during Treadmill and Overground Running

Running stability is the ability to withstand naturally occurring minor perturbations during running. It is susceptible to external and internal running conditions such as footwear or fatigue. However, both its reliable measurability and the extent to which laboratory measurements reflect outdoor running remain unclear. This study aimed to evaluate the intra- and inter-day reliability of the running stability as well as the comparability of different laboratory and outdoor conditions. Competitive runners completed runs on a motorized treadmill in a research laboratory and overground both indoors and outdoors. Running stability was determined as the maximum short-term divergence exponent from the raw gyroscope signals of wearable sensors mounted to four different body locations (sternum, sacrum, tibia, and foot). Sacrum sensor measurements demonstrated the highest reliabilities (good to excellent; ICC = 0.85 to 0.91), while those of the tibia measurements showed the lowest (moderate to good; ICC = 0.55 to 0.89). Treadmill measurements depicted systematically lower values than both overground conditions for all sensor locations (relative bias = -9.8% to -2.9%). The two overground conditions, however, showed high agreement (relative bias = -0.3% to 0.5%; relative limits of agreement = 9.2% to 15.4%). Our results imply moderate to excellent reliability for both overground and treadmill running, which is the foundation of further research on running stability

Gamma oscillations in the temporal pole reflect the contribution of approach and avoidance motivational systems to the processing of fear and anger words

Prior reports suggest that affective effects in visual word processing cannot be fully explained by a dimensional perspective of emotions based on valence and arousal. In the current study, we focused on the contribution of approach and avoidance motivational systems that are related to different action components to the processing of emotional words. To this aim, we compared frontal alpha asymmetries and brain oscillations elicited by anger words associated with approach (fighting) motivational tendencies, and fear words that may trigger either avoidance (escaping), approach (fighting) or no (freezing) action tendencies. The participants’ task was to make decisions about approaching or distancing from the concepts represented by words. The results of cluster-based and beamforming analyses revealed increased gamma power band synchronization for fear words relative to anger words between 725 and 750 ms, with an estimated neural origin in the temporal pole. These findings were interpreted to reflect a conflict between different action tendencies underlying the representation of fear words in semantic and emotional memories, when trying to achieve task requirements. These results are in line with the predictions made by the fear-hinders-action hypothesis. Additionally, current data highlights the contribution of motivational features to the representation and processing of emotional wordsThis study was supported by the Ministerio de Ciencia, Innovación y Universidades of Spain (Grants PGC2018- 098558-B-I00, PID2019-107206GB-I00, and RED2018-102615- T), Ministerio de Economía y Competitividad of Spain (Grant PSI2017-84922-R), Comunidad de Madrid (Grants H2019/HUM-5705 and SI1/PJI/2019-00061), Universitat Rovira i Virgili (Grant 2019PFR-URV-B2-32). DH-P was funded by a predoctoral FPU20/03345 gran

Peritoneal dialysis associated-peritonitis: a preventable complication

Peritoneal dialysis is useful renal replacement therapy for patients with end-stage chronic kidney disease. Latin America has 30% of the world population in peritoneal dialysis and within these countries Mexico covers 73% of them. In our country, the Mexican institute of social security (IMSS by its Spanish acronym) serves more than half of the Mexican population that requires renal replacement therapy. In 2014 it represented 15% of total annual cost of the institution. Peritonitis in peritoneal dialysis is the main complication seen in this renal replacement therapy with morbidity and mortality from 2 to 6%. The epidemiology of peritonitis associated with peritoneal dialysis varies according to the continent, country and dialysis center. The rate of peritonitis per year of each center reflects their quality of care. The prevention, diagnosis and treatment of peritonitis impact in the quality of life of the patient, the success of renal replacement therapy, public health costs and associated mortality. This review addresses the epidemiology, diagnosis, treatment, and preventive measures of peritonitis, focused on the procedures for improving the standards of care