Modelo farmacocinético de florfenicol en tilapias (Oreochromis niloticus) sometidas a diferentes temperaturas de crianza.

El objetivo de este trabajo fue desarrollar un modelo farmacocinético de florfenicol en plasma de tilapia (Oreochromis niloticus) sometido a diferentes temperaturas de crianza para estimar la concentración plasmática de los protocolos indicados en los prospectos de productos de florfenicol autorizados en Brasil. Para ello, se creó un modelo farmacocinético a partir de datos previamente publicados sobre la concentración plasmática de florfenicol en tilapia del Nilo sometida a diferentes temperaturas. La construcción del modelo farmacocinético se realizó con el programa Monolix 2020R1 de Lixoft®, partiendo de los datos de farmacocinética plasmática de florfenicol encontrados en la literatura. Las concentraciones plasmáticas de florfenicol se estimaron a partir de tratamientos con dosis de 10, 15 y 20 mg/kg administradas cada 24 horas durante 10 días, a temperaturas de 18, 21, 26 y 30°C, utilizando el programa Simulx 2020 de Lixoft®. Los parámetros de tiempo de latencia de absorción (Tlag) y aclaramiento (Cl) mostraron una correlación positiva con la temperatura, mientras que la constante de absorción (Ka) mostró una correlación negativa. Asimismo, se puede observar que los animales mantenidos a 30 ºC tienen una mediana de la concentración plasmática móvil de aproximadamente la mitad que los animales criados a 18 ºC y tratados con las mismas dosis. Por otra parte, las dosis crecientes determinaron un aumento de aproximadamente el doble de las medianas de la concentración plasmática. El modelo propuesto permitió cuantificar el impacto de la temperatura en los parámetros farmacocinéticos, además de estimar las concentraciones plasmáticas de florfenicol para tilapia a diferentes temperaturas de crianza

Optical Nanoantennas for Multiband Surface-Enhanced Infrared and Raman Spectroscopy

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Disordered protein-graphene oxide co-assembly and supramolecular biofabrication of functional fluidic devices

Supramolecular chemistry offers an exciting opportunity to assemble materials with molecular precision. However, there remains an unmet need to turn molecular self-assembly into functional materials and devices. Harnessing the inherent properties of both disordered proteins and graphene oxide (GO), we report a disordered protein-GO co-assembling system that through a diffusion-reaction process and disorder-to-order transitions generates hierarchically organized materials that exhibit high stability and access to non-equilibrium on demand. We use experimental approaches and molecular dynamics simulations to describe the underlying molecular mechanism of formation and establish key rules for its design and regulation. Through rapid prototyping techniques, we demonstrate the system's capacity to be controlled with spatio-temporal precision into well-defined capillary-like fluidic microstructures with a high level of biocompatibility and, importantly, the capacity to withstand flow. Our study presents an innovative approach to transform rational supramolecular design into functional engineering with potential widespread use in microfluidic systems and organ-on-a-chip platforms

Validation of high performance liquid chromatography method for determination of meloxicam loaded PEGylated nanocapsules

abstract A method to ensure that an analytical method will produce reliable and interpretable information about the sample must first be validated, making sure that the results can be trusted and traced. In this study, we propose to validate an analytical high performance liquid chromatography (HPLC) method for the quantitation of meloxicam loaded PEGylated nanocapsules(M-PEGNC). We performed a validation study, evaluated parameters including specificity, linearity, quantification limit, detection limit, accuracy, precision and robustness. PEGylated nanocapsules were prepared by interfacial deposition of preformed polymer, and the particle size, polydispersity index, zeta potential, pH value and encapsulation efficiency were characterized. The proposed HPLC method provides selective, linear results in the range of 1.0-40.0 μg/mL; quantification and detection limits were 1.78 μg/mL and 0.59 μg/mL, respectively; relative standard deviation for repeatability was 1.35% and intermediate precision was 0.41% and 0.61% for analyst 1 and analyst 2, respectively; accuracy between 99.23 and 101.79%; robustness between 97.13 and 98.45% for the quantification of M-PEGNC. Mean particle diameters were 261 ± 13 nm and 249 ± 20 nm, polydispersity index was 0.15 ± 0.07 and 0.17 ± 0.06, pH values were 5.0 ± 0.2 and 5.2 ± 0.1, and zeta-potential values were -37.9 ± 3.2 mV e -31.8 ± 2.8 mV for M-PEGNC and placebo(B-PEGNC), respectively. In conclusion, the proposed analytical method is suitable for the quality control of M-PEGNC. Moreover, suspensions showed monomodal size distributions and low polydispersity index indicating high homogeneity of formulations with narrow size distributions, and appropriate pH and zeta potential. The extraction process was efficient for release of meloxicam from nanostructured systems

Preparation of mupirocin-loaded polymeric nanocapsules using essential oil of rosemary

Abstract The purpose of this study was to prepare and characterize mupirocin-loaded polymeric nanocapsules using two different oils and to develop and validate an analytical method for quantitative determination by high performance liquid chromatography. The mean size of the nanoparticles was 233.05 nm and 275.03 nm for nanocapsules with a rosemary oil like oily core and caprylic/capric triglyceride, respectively, and a good polydispersity index below 0.25 for both formulations. The nanocapsules showed good stability when stored at 40 ºC and room temperature for 30 days. The quantitative method was performed with a mobile phase consisting of ammonium ammonium acetate (0.05 M adjusted to pH 5.0 with acetic acid) and acetonitrile 60:40 (v/v); the flow rate was 0.8 mL/min, UV detection at 230 nm. The analytical method was linear in the range of 5.0-15.0 µg/mL, specific for both oils, accurate, precise (intermediate precision RSD = 1.68% and repeatability RSD = 0.81%) and robust under the evaluated conditions. Therefore, this method can be performed for quantification of mupirocin in polymeric nanocapsules containing both oils