Browsing by Autor "Antonio Nogueira"

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Desempeño del método cromatográfico para el estudio de estabilidad del aceite de hígado de tiburón microencapsulado empleando acetato de quitosana
(Facultad de Farmacia, 2016) Caridad García; Mirna Fernández Cervera; Mirta Castiñeira; Vivian Martínez; Orestes Darío López Hernández; Antonio Nogueira
Objetivo: Evaluar el desempeño del método para la cuantificación de la vitamina A en el aceite microencapsulado, empleando acetato de quitosana y maltodextrina como agentes encapsulantes, así como estudiar la estabilidad del aceite microencapsulado. Materiales y métodos: Los parámetros evaluados se correspondieron con lo establecido internacionalmente para este estudio: especificidad, exactitud y precisión. El estudio de estabilidad se realizó durante 12 meses a temperatura ambiente (30 ± 2 OC) y 70 ± 5 % de humedad relativa, evaluándose en el tiempo la eficiencia de encapsulación, aceite superficial, pérdidas por desecación, contenido de vitamina A y conteo microbiológico. Resultados: Se demostró que el método evaluado fue específico, preciso y exacto para la determinación del contenido de vitamina A en la mezcla de aceite microencapsulado. Los resultados demuestran que el aceite microencapsulado tiene un comportamiento estable en cuanto a los indicadores evaluados, evidenciándose la protección ofrecida por los componentes de la pared de las microcápsulas. Conclusiones: El método empleado en la cuantificación de la vitamina A en el aceite microencapsulado resultó específico, exacto y preciso, demostrándose su aplicabilidad para el control de calidad y estudio de estabilidad. El aceite microencapsulado con acetato de quitosana y maltodextrina como agentes encapsulantes, es estable física, química y microbiológicamente, durante 12 meses.
Estabilidad del aceite de hígado de tiburón microencapsulado vs. pool de aceite
(2015) Caridad García; Mirna Fernández Cervera; Mirta Castiñeira; Claudia Buendía; Brian Martínez; Orestes Darío López Hernández; Antonio Nogueira
El estudio de estabilidad del aceite microencapsulado y sin microencapsular se realizó por el método de vida de estante a las temperaturas de 2-8 °C, y temperatura ambiente, respectivamente, durante doce meses. Los parámetros analizados al pool de aceite fueron: características organolépticas, índice de acidez, peróxido, saponificación, contenido de vitamina A y conteo microbiológico. Mientras que al aceite microencapsulado se le evaluaron las características organolépticas, la eficiencia de encapsulación, contenido de humedad, aceite superficial, contenido de vitamina A y conteo microbiológico. Los resultados evidenciaron una disminución superior al 5% en el contenido de vitamina A en el aceite sin microencapsular, a diferencia del aceite microencapsulado. Se logró el enmascaramiento del olor intenso a pescado, y los restantes parámetros evaluados se encontraron dentro de los límites establecidos.El aceite de hígado de tiburón microencapsulado resultó estable física, química y microbiológicamente por doce meses, mientras que el aceite sin microencapsular solo seis meses. El proceso de microencapsulación no solo mejoró sus características organolépticas, sino también favoreció su estabilidad lográndose un mayor período de vida útil.
In vitro release of dibucaine hydrochloride from chitosan semisolid vehicles: emulsion and hydrophilic gels
(2017) Nilia de la Paz; Dania Pérez; Mirna Fernández Cervera; Caridad García; Vivian Martínez; Antonio Nogueira; Oscar García
Context: Chitosan has received attention as a functional, sustainably renewable, nontoxic and biodegradable biopolymer for pharmaceutical applications. Aims: To evaluate the release of dibucaine hydrochloride from semisolid vehicles of oil/aqueous type emulsion and aqueous gels, stabilized by using chitosan (CH) or chitosan acetate (CHAc). Methods: Emulsions were developed by varying the emulsifying agent: polysorbate 80, CH or CHAc and by combining CH with polysorbate 80 or CHAc with polysorbate 80. The hydroxypropylmethyl cellulose F4M was added as a stabilizing agent in gel formulations. The release rates of model drug from semisolid vehicles were measured by using a dialysis sac. Drug release was also quantified by using a validated UV-VIS spectrophotometric method. Results: The pH values showed minimal changes for emulsion and gel formulations. The drug is a cationic salt, and it is not able to bind polymer cations by electrostatic repulsion. The rheological property of the vehicle type emulsion was adjusted to plastic and pseudo-plastic fluid to the gels. The drug release was independent of the viscosity of vehicles. Dibucaine release from both types of formulation was found to follow a square-root-of-time kinetic model, but a higher rate of release was obtained from gel formulations. Conclusions: It was shown that chitosan was adsorbed to the surface of polysorbate 80-coated droplets, and that the electrostatic attraction between the non-ionic surfactant and the drug retarded its release from a semisolid system. The multilayer emulsions showed more influence of the release of drug than CH or CHAc single layer emulsion.
Performance of chromatographic method for the stability study of microencapsulated shark liver oil using chitosan acetate
(Universidad de Granada, 2016) Caridad García; Mirna Fernández Cervera; Mirta Castiñeira; Vivian Martínez; Orestes Darío López Hernández; Antonio Nogueira
Physical stability of emulsion and hydrophilic gels with chitosan and chitosan acetate
(2017) Nilia de la Paz; Dania Pérez; Mirna Fernández Cervera; Dulce M Soler; Yanet Rodríguez; Antonio Nogueira
Context: Chitosan has received great attention because it is a functional, biodegradable, renewable and non-toxic biopolymer with multiple pharmaceutical applications, including stabilizing agent. Aims: To evaluate the physical stability of emulsified bases and hydrophilic gels containing chitosan or chitosan acetate as stabilizing agents. Methods: Stability of shelf-life formulations at room temperature and in refrigeration was evaluated over a period of 60 days and by thermal stress testing and centrifugal destabilization. The organoleptic characteristics, pH, conductivity and flow behavior were evaluated, the latter through the analysis of the rheograms, the determination of rheological parameters (consistency index, apparent viscosity, creep value and flow index), as well as their comparison statistics. The possible correlations between these parameters and the concentration of the biopolymers were also evaluated. Results: The bases elaborated with chitosan or its soluble derivative showed adequate physical stability during the study time. The effect of the storage temperature, as well as the type and concentration of the stabilizing agent used was evidenced. Emulsifier combinations provided less stability. A linear correlation between the rheological parameters and the biopolymer concentration was evidenced. Conclusions: Chitosan and chitosan acetate can be used as emulsifying agents in semi-solid and gelling bases in hydrophilic gels, due to the electrostatic stabilization and the viscosity they contribute to the system in relation to its concentration.
Spray drying of shark liver oil pool: Effects on physical-chemical properties and antioxidant capacity
(2018) Caridad García; Mirna Fernández Cervera; Orestes Darío López Hernández; Liván Delgado-Roche; Antonio Nogueira; Mirta Castiñeira; Esteban A. Medrano
Context: Spray-drying is a technique used to produce encapsulated products, thus improving the stability of components as well as their organoleptic characteristics. Aims: To evaluate the effect of microencapsulation of shark liver oil pool by spray drying on its physical-chemical properties and antioxidant capacity. Methods: A mix design was created with a constant load of oil, made possible by controlling the proportion between chitosan acetate and maltodextrin. Loss on drying, encapsulation efficiency and yield were determined for the microcapsules. Reversed-phase HPLC analysis was used in order to determine the vitamin A content in microencapsulated and non-microencapsulated oil, as well as its delivery from the dried product. Vitamin A was the active compound used as a chemical marker. The following parameters were also evaluated: organoleptic characteristics, moisture content, particle size, surface morphology and antioxidant capacity. Results: The encapsulation efficiency of microencapsulated oil increased slightly as the concentration of chitosan acetate increased. In order to achieve a greater encapsulation efficiency and a lower moisture content in microencapsulated oil, the proportion between chitosan acetate and maltodextrin should be maintained at 35% and 35% each, according to established manufacturing conditions. Both polymers prevent oil from leaving the droplet. This is a very important factor in storage stability of vitamins and fatty acids, which are subject to oxidative deterioration. Conclusions: Spray-drying microencapsulation of pool oil does not affect vitamin A content or delivery; fatty acid content and antioxidant capacity are also not affected.
Stability of spray-dried chitosan salts derived from lobster chitin as a raw material
(Facultad de Farmacia, 2015) Nilia de la Paz; Caridad García; Mirna Fernández Cervera; Lisandra de la Caridad Núñez García; Vivian Martínez; Orestes Darío López Hernández; Antonio Nogueira
Objetivos. Desarrollar y validar un mtodo para la determinacin del grado de desacetilacin molar del acetato de quitosana y lactato de quitosana, y realizar el estudio de estabilidad de ambas sales.
Validación de un método cromatográfico aplicable al control de calidad y estudio de estabilidad del pool de aceite hígado de tiburón microencapsulado
(2014) Margarita García Caridad; Mirna Fernández Cervera; Mirta Castiñeira; Vivian Martínez; Darío López Orestes; Antonio Nogueira
Aim: The purpose of this study was to validate, in accordance with international standards, a chromatographic method to determine the vitamin A in the pool of shark liver oil microencapsulated.Materials and Methods: The valued parameters belonged together with what settles down internationally for technical quantitative, among those that we can mention: specificity, lineality, accuracy, precision, robustness and detection and quantification limits. The method based on the separation from the vitamin A to inclination a chromatographic column Lichrosorb RP - 18 to a wavelength of 325 nm, using a mobile phase composed by methanol: water, of proportion 90:10, and the quantification of the same ones in front of referee samples using the method of the external standard.Results: It was demonstrated that the developed procedure, was the sufficiently lineal thing, with a detection limit of 2 μg/mL and 6 μg/mL like quantification limit, specific, precise, exact and robust for the determination of the vitamin A content in the pool of microencapsulated oil, for what can be an employee in the quality control and stability study.Conclusions: The determination of the vitamin A content in the microencapsulated pool of shark liver oil, through a method for high resolution liquid chromatography, was specific, lineal, precise, exact and robust, for quality control and stability study.