Study of some volumetric properties of the pharmaceutical model solvent system ethanol + ethyl acetate at several temperatures

The binary solvent system ethanol + ethyl acetate is widely used in the pharmaceutical sciences as a versatile model for studying the solubility of drugs. In this context, the excess molar volumes and the partial molar volumes of components were investigated from density measurements on the entire range of mass fractions, for this system at 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K. The excess molar volumes were fitted by Redlich-Kister equation by using third degree polynomials and compared with those reported in the literature for other solvent systems. The system tested exhibited positive excess volumes (up to 0.18 cm3 mol-1 at 313.15 K), probably due to weak interactions, like dispersion forces, between unlike molecules or, some differences in the molar volumes of pure components. The effect of temperature on the different volumetric properties studied was also analyzed.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Study of some volumetric properties of the pharmaceutical model solvent system ethanol + ethyl acetate at several temperatures

The binary solvent system ethanol + ethyl acetate is widely used in the pharmaceutical sciences as a versatile model for studying the solubility of drugs. In this context, the excess molar volumes and the partial molar volumes of components were investigated from density measurements on the entire range of mass fractions, for this system at 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K. The excess molar volumes were fitted by Redlich-Kister equation by using third degree polynomials and compared with those reported in the literature for other solvent systems. The system tested exhibited positive excess volumes (up to 0.18 cm3 mol-1 at 313.15 K), probably due to weak interactions, like dispersion forces, between unlike molecules or, some differences in the molar volumes of pure components. The effect of temperature on the different volumetric properties studied was also analyzed.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Osmotic and activity coefficients of aqueous solutions of the anesthetic drugs lidocaine-HCl and procaine-HCl at 298.15 K

Osmotic and activity coefficients were measured for aqueous solutions of Lidocaine-HCl and Procaine-HCl using the isopiestic method at 298.15 K. The results were fitted to the Pitzer equation and the parameters were calculated. A good correlation with the Pitzer model was found. The osmotic coefficients thus obtained were analyzed by comparing them with the Debye-Hückel limiting law. The results are discussed in terms of ion-solvent and ion-ion interactions.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Osmotic and activity coefficients of aqueous solutions of the anesthetic drugs lidocaine-HCl and procaine-HCl at 298.15 K

Osmotic and activity coefficients were measured for aqueous solutions of Lidocaine-HCl and Procaine-HCl using the isopiestic method at 298.15 K. The results were fitted to the Pitzer equation and the parameters were calculated. A good correlation with the Pitzer model was found. The osmotic coefficients thus obtained were analyzed by comparing them with the Debye-Hückel limiting law. The results are discussed in terms of ion-solvent and ion-ion interactions.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Extended hildebrand solubility approach in the solubility estimation of the sunscreen ethylhexyl triazone in ethyl acetate + ethanol mixtures

Ethylhexyl triazone (EHT) is a sunscreen agent widely used in the formulation of skin care products, whose physicochemical properties have not been thoroughly studied. In this work the Extended Hildebrand Solubility Approach (EHSA) was applied to evaluate the solubility of EHT in ethyl acetate + ethanol mixtures at 298.15 K. A good correlative capacity of EHSA was found using a regular polynomial model in order five (overall deviation lower than 1.2 %), when the W interaction parameter is related to the solubility parameter of the mixtures. Besides, the deviations obtained in the estimated solubility with respect to experimental solubility were lower compared with those obtained directly by means of an empiric regression of the experimental solubility as a function of the mixtures' solubility parameters.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Extended hildebrand solubility approach in the solubility estimation of the sunscreen ethylhexyl triazone in ethyl acetate + ethanol mixtures

Ethylhexyl triazone (EHT) is a sunscreen agent widely used in the formulation of skin care products, whose physicochemical properties have not been thoroughly studied. In this work the Extended Hildebrand Solubility Approach (EHSA) was applied to evaluate the solubility of EHT in ethyl acetate + ethanol mixtures at 298.15 K. A good correlative capacity of EHSA was found using a regular polynomial model in order five (overall deviation lower than 1.2 %), when the W interaction parameter is related to the solubility parameter of the mixtures. Besides, the deviations obtained in the estimated solubility with respect to experimental solubility were lower compared with those obtained directly by means of an empiric regression of the experimental solubility as a function of the mixtures' solubility parameters.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Volúmenes molares aparentes de los anestésicos procaína-HCl y lidocaína-HCl en agua a temperaturas entre 278,15 y 313,15 K

La lidocaína-HCl y procaína-HCl son anestésicos locales ampliamente usados en procedimientos quirúrgicos menores, sin embargo la información fisicoquímica acerca de su comportamiento volumétrico, así como de otras propiedades fisicoquímicas, aún es incompleta en la actualidad. Por esta razón, en este artículo se presentan los valores de densidad de algunas soluciones acuosas de estos dos fármacos en función de la concentración (desde 0,0500 hasta 0,5000) mol kg–1 a diferentes temperaturas (278,15, 283,15, 288,15, 293,15, 298,15, 303,15, 308,15 y 313,15 K). Así mismo se presentan los volúmenes molares aparentes y volúmenes molares parciales a dilución infinita de los fármacos como electrolitos, y de otro lado, los volúmenes molares parciales a dilución infinita de los fármacos moleculares y las expansibilidades molares, los cuales fueron calculados a partir de los valores de densidad y composición de las mezclas. Los resultados obtenidos se interpretan en términos de interacciones soluto-solvente.Lidocaine-HCl and procaine-HCl are local anesthetic drugs widely used in minor chirurgic procedures, nevertheless, physicochemical information about their volumetric behavior, as well as for other aqueous properties, is not complete at present. In this context, in this article, densities of aqueous solutions of both drugs have been measured as a function of concentration (from 0.0500 to 0.5000) mol kg–1 at several temperatures, i.e. 278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15 K. The apparent molar volumes and partial molar volumes at infinite dilution for the electrolyte drugs were calculated, whereas, the partial molar volumes at infinite dilution and partial molar expansibilities for the molecular forms were also calculated. The dependence of these properties with temperature is shown. The results are interpreted in terms of interaction solute-solvent.Fil: Delgado, Daniel R.. Universidad Nacional de Colombia; ColombiaFil: Jimenez Kairuz, Alvaro Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Manzo, Ruben Hilario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Vargas, Edgar F.. Universidad de los Andes; ColombiaFil: Martinez, Fleming. Universidad Nacional de Colombia; Colombi

Osmotic and activity coefficients of aqueous solutions of the anesthetic drugs lidocaine-HCl and procaine-HCl at 298.15 K

Osmotic and activity coefficients were measured for aqueous solutions of Lidocaine-HCl and Procaine-HCl using the isopiestic method at 298.15 K. The results were fitted to the Pitzer equation and the parameters were calculated. A good correlation with the Pitzer model was found. The osmotic coefficients thus obtained were analyzed by comparing them with the Debye-Hückel limiting law. The results are discussed in terms of ion-solvent and ion-ion interactions.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Necrotizing entercolitis: socio-demographic, clinical and histopathological findings in a series of neonatal autopsies

La enterocolitis necrotizante es un trastorno caracterizado por la necrosis isquémica de la mucosa intestinal, es la enfermedad gastrointestinal más grave que afecta a los neonatos, con alta morbilidad y mortalidad, principalmente en prematuros. El objetivo del presente estudio es describir las características clínicas y anatomopatológicas de los recién nacidos fallecidos con enterocolitis necrotizante, diagnosticados en un hospital de alta complejidad. Metodología. Este es un estudio descriptivo retrospectivo de 21 casos de autopsias médico-científicas hechas en un hospital de alta complejidad del nororiente colombiano, con hallazgos anatomopatológicos de enterocolitis necrotizante, realizadas entre enero de 2013 y julio de 2017. Resultados. El 85.7% de los recién nacidos eran pretérminos, un igual porcentaje presentaba un peso menor a 2,500 gramos al nacer. Respecto a los antecedentes maternos el 14.3% tuvieron espectro de trastornos hipertensivos asociados al embarazo y el 23.8% infección materna. Los tres sitios más frecuentes de ubicación de enterocolitis necrotizantes fue íleon, colon ascendente y colon transverso. Discusión. Según algunos autores, hasta el 85% de todos los casos de enterocolitis necrotizante ocurren en pacientes prematuros, especialmente en bebés con peso extremadamente bajo al nacer. Hay formas de enterocolitis necrotizante que ocurren en bebés a término y, generalmente, están asociadas con factores predisponentes, resultados compatibles con lo que encontramos en esta investigación. Conclusiones. Este estudio elaborado con población colombiana se correlaciona con lo descrito en la población mundial en la cual la enterocolitis necrotizante se presenta más en los recién nacidos pretérmino y con bajo peso al nacer.Necrotizing entercolitis is a disorder characterized by the ischemic necrosis of intestinal mucosa. It is the most serious gastrointestinal disease affecting neonates, with high morbidity and mortality rates, mainly among premature newborns. The purpose of this study is to describe the clinical and anatamo-pathological characteristics of deceased newborns with necrotizing entercolitis, diagnosed at a high-complexity hospital. Methodology. This is a descriptive retrospective study of 21 cases of medical-scientific autopsies performed at a high-complexity hospital in northeastern Colombia, with anatomo-pathological findings of necrotizing entercolitis, performed between January 2013 and July 2017. Results. 85.7% of the newborns were pre-term, and the same percentage had weight at birth below 2.5 kilograms. Regarding the mothers’ background, 14.3% displayed a spectrum of hypertensive disorders associated with pregnancy, and 23.8% had maternal infections. The three most frequent locations of necrotizing entercolitis were the ileum, ascending colon and transverse colon. Discussion. According to some authors, up to 85% of all cases of necrotizing entercolitis occur in premature patients, especially in babies with extremely low weight at birth. There are forms of necrotizing entercolitis that occur in full term babies, and they are generally associated with contributing factors, which is consistent with the findings of this study. Conclusions. This study of a Colombian population is consistent with other descriptions of the global population, where necrotizing entercolitis arises more frequently in pre-term newborns and low weight at birth

Apparent molar volumes of sodium naproxen in water at several concentrations and temperatures

Densities of aqueous solutions of sodium naproxen have been measured as functions of concentration (from 0.0250 to 0.5000 mol kg-1 ) and temperature (from 278.15 to 313.15 K). The apparent molar volumes, partial molar volumes at infinite dilution and partial molar expansibility were calculated. The dependence of these properties with temperature is also shown. The results are interpreted in terms of solute-solvent interactions.Colegio de Farmacéuticos de la Provincia de Buenos Aire