Oscar A Florez

With the purpose of enabling the analysis by digital methods of particles of multisource pharmaceutical raw materials, this study analyzed different crystal habits of ampicillin particles, by grouping the external shapes obtained from 3 different solvents (acetonitrile, ethanol, and methanol), thereby reducing the number of descriptors necessary to adequately represent each shape. For this purpose, a selection of morphological descriptors was used including: circularity, roughness, roundness, compactness, aspect ratio, effective diameter, solidity, convexity, fractal dimension, and 10 Complex Fourier descriptors. These measures cover highly diverse morphological properties and define the crystal habit of a particle. Principal Component Analysis (PCA) and the Cluster Analysis (CA) were the grouping techniques used, which demonstrated the possibility of using between 2 and 4 descriptors instead of the 18 proposed initially.

Los agentes antimicrobianos son, con frecuencia, los productos que generan más dudas en cuanto su efecto terapéutico, ya que no son pocos los casos en los cuales se ha presentado diferente eficacia clínica entre productos de un mismo principio activo pero de diferentes laboratorios; por lo tanto, es necesario realizar estudios que puedan proporcionar respuestas al por qué de estas variaciones en estos principios activos, y que apunten a acabar o, por lo menos, reducir,las eventuales diferencias entre estos productos terapéuticos. En este sentido, este trabajo busca evaluar los resultados de las características fundamentales (forma externa, estructura interna, e identificación física y química) de ampicilina en polvo, utilizando un producto de marca (polvo en cápsulas), uno genérico (polvo en cápsulas), y diferentes formas cristalinas de la materia prima (en polvo), obtenidas por recristalización en diferentes solventes y a temperatura ambiente. Luego de determinar las propiedades fu...

El presente estudio busca elaborar y caracterizar un producto denominado fibra, a partir de los residuos resultantes del procesamiento de la naranja, limon, mandarina, pina y maracuya. Para justificar el empleo como materia prima de estas fibras, se efectua el analisis cuantitativo limitandose al contenido de humedad, cenizas, fibra cruda, proteina cruda, carbohidratos totales, ademas del contenido de hierro, fosforo, fibra dietaria total, fibra dietaria soluble y fibra dietaria insoluble. Los resultados muestran estos productos como fuentes muy altas de fibra dietaria tanto soluble como insoluble, con buen contenido de hierro, fosforo, y otros nutrientes a excepcion de la grasa cruda. Este conocimiento permite formular recomendaciones para su empleo en productos alimenticios y farmaceuticos.

ABSTRACT The TiO2 photocatalytic degradation of oxacillin (OXA) in synthetic and natural waters was studied. The matrix effects, in terms of antibiotic and antimicrobial activity removal, were evaluated in the presence of iron ions, natural mineral water and additives contained in commercial formulations of the antibiotic. A slight improvement in degradation was observed in the presence of iron ions. On the other hand, the presence of excipients in a commercial formulation or inorganic ions in natural mineral water slightly inhibited the efficiency of the system. An experimental design using pH, catalyst load and light intensity as variables was also evaluated. The best performances were achieved at natural pH (∼6.0) using 2.0 g L−1 of TiO2 with 150 W of applied power. The evaluation of OXA concentration indicated that the photodegradation process showed a Langmiur–Hinshewoold kinetic model. The extent of the process was evaluated following the evolution of chemical oxygen demand (COD) and dissolved organic carbon (DOC). Total removal of both, the antibiotic and its antimicrobial activity, was achieved after 120 min; while 100% of mineralization was observed within 480 min of treatment. Finally, five by-products were identified, the degradation routes were elucidated and a schema of the antibiotic degradation was proposed.

ABSTRACT In this work the application of electrochemical anodic oxidation for the removal of the β-lactam antibiotic Oxacillin (OXA) was tested. The study was performed using an undivided stirred tank reactor equipped with a DSA (Ti/IrO2) anode and a zirconium spiral cathode. A statistical design of experiments was used to study the influence of different operating variables: substance concentration (6.0–1624.0 μmol L−1), current density (3.25–30.25 mA cm−2) and NaCl concentration (0.05–0.4 mol L−1). According to the Pareto chart, current density was the main variable influencing OXA degradation, followed by NaCl concentration. The effect of the initial pH and type of supporting electrolyte was also evaluated. The latter lead to the identification of different degradation routes which depended on the electrolyte employed. By using the best electrolyte and current density, complete OXA removal and total loss of antimicrobial activity was achieved after only 4 min of treatment. The efficiency in the oxacillin degradation was not significantly affected by the initial pH (3–9). Interestingly, no mineralization was observed even after long exposure times (8 h). However, 70% of the initial chemical oxygen demand (COD) was eliminated and the level of biodegradability (BOD5/COD) increased from 0.03 to 0.84, indicating that the system is able to transform the pollutant into highly oxidized and biodegradable bio-products with no antimicrobial activity. Additionally, different substances and radical scavengers present in wastewaters and natural water did not significantly affect the efficiency of the process. Finally, the more relevant initial aromatic by-products were identified and a degradation schema of the electrochemical oxidation of the OXA antibiotic was proposed.

The sonochemical degradation of dicloxacillin (DXC) was studied in both synthetic and natural waters. Degradation routes and the effect of experimental conditions such as pH, initial DXC concentration and ultrasonic power were evaluated. Experiments were carried out with a fixed frequency (600kHz). The best performances were achieved using acidic media (pH=3) and high power (60W). The degradation process showed pseudo-first order kinetics as described by the Okitsu model. To evaluate water matrix effects, substrate degradation, in the presence of Fe(2+) and organic compounds such as glucose and 2-propanol, was studied. A significant improvement was achieved with Fe(2+) (1.0mM). Inhibition of the degradation process was observed at a relatively high concentration of 2-propanol (4.9mM), while glucose did not show any effect. Natural water showed an interesting effect: for a low concentration of DXC (6.4μM), an improvement in the degradation process was observed, while at a higher concentration of DXC (0.43mM), degradation was inhibited. Additionally, the extent of degradation of the process was evaluated through the analysis of chemical oxygen demand (COD), antimicrobial activity, total organic carbon (TOC) and biochemical oxygen demand (BOD5). A 30% removal of COD was achieved after the treatment and no change in the TOC was observed. Antimicrobial activity was eliminated after 360min of ultrasonic treatment. After 480min of treatment, a biodegradable solution was obtained.

ARTÍCULOS ORIGINALES. Glicinato de cobre: una aproximación a su solubilidad. Copper glycinate: an approach to its solubility. Gloria Elena Tobón Zapata I ; Julie Fernanda Benavides Arevalo II ; Oscar Albeiro Flórez Acosta III. I Doctora en Química. ...