Mebendazole spectrophotometric determination: theorical and experimental study of the interaction with sodium hydroxide

USP, EP, and Argentinian Pharmacopoeia proposed HPLC-UV for quantitative quality control of mebendazole (MBZ) tablets. In this work, a spectrophotometric method is proposed. A mebendazole solution was prepared by dissolving the active ingredient in an ethanolic solution of HCl (1: 100) and adding NaOH 3N. It was allowed to stand 10 minutes. Absorbance spectrum was scanned between 350 and 700 nm. Maximum was found at 400 nm. A calibration curve in the range of 0.05 to 0.25 mg / mL, responded to A = (2.2746 ± 0.0224) C + (0.0012 ± 0.0068) with R2 = 0.9999. The RSD% was 0.961 indicating good repeatability for the analytical procedure. Accuracy in recovery experience was found to be 99.2 - 100.6%. Statistical comparison using t -test and F ?test indicate that there are no significant differences between HPLC and the spectrophometric methods, whith a 95% confidence level. Specificity and intermediate precision assays were satisfactory. Quantum theoretical chemistry was applied to elucidate the interaction that gives origin to the color, using static approximation and density functional theory, B3LYP and base 6-311G (d, p). Excitation energies B3LYP for MBZ and MBZ product of the interaction with sodium atom, were coincidental with experimental results.Fil: Delfino, Mario Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Monzón, Celina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Jorge, Nelly Lidia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; ArgentinaFil: Sarno, María del Carmen Teresa. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentin

Fast and Efficient Monitoring of Diclofenac Dissolution Profile by CE

Capillary electrophoresis (CE) was used to follow Diclofenac tablet dissolution, in very short times and allowing dissolution testing without volume replacement. By using Student´s t test and F-test, this CE method was compared with HPLC. Statistical data show that there are no significant differences among them. The drug release kinetic of diclofenac tablets was described by various mathematical models and equations. Model-Independent Methods: t50% = 10.34 min; t80% = 20 min; DE% = 79.41% and MDT = 10.85 min, show that diclofenac tablet dissolution rate is very high, having 80% drug dissolution within 20 minutes. Model-Dependent Methods. The kinetics models used were: zero order, first order, Hixson?Crowell cube root law, Higuchi model, and Weibull model. Criteria used to choose the best model was by comparisson of r2 and AIC (Akaike Information Criteria). The model that best adjusts diclofenac tablet dissolution profile was the Hixson-Crowell cube root model.Fil: Monzón, Celina María. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Vera Candioti, Luciana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Departamento de Química. Cátedra de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Sarno, María del Carmen Teresa. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; ArgentinaFil: Delfino, Mario Raul. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Dosage of atenolol tablets by spectrophotometry with phenol red

A spectrophotometric method is proposed for the analysis of atenolol, based on its reaction with the indicator phenol red in an acetone environment. Experimental conditions for the formation of an ion pair complex peaking at 388 nm were optimized. The method is linear in the range of 1 to 5 mg/mL with a correlation coefficient (n = 30) of 0.9968. Stoichiometry of the reaction is 1: 1. Free energy change (ΔG) for complex formation and stability constant (KF) have been calculated. Working with placebo it was found that excipients do not interfere in the analysis. The proposed method was applied to tablets provided by the Medicinal Plant of Corrientes (Plamecor), Argentina. Recoveries from 99.67 to 100.17 were achieved. Results were compared (F test and t test) favorably with those given by official methods. (HPLC - UV).Colegio de Farmacéuticos de la Provincia de Buenos Aire

Diclofenac quantification: analytical attributes of a spectrophotometric method

An spectrophotometric UV-visible technique used to quantify diclofenac and its application to pharmaceutical preparations is described, based on diclofenac oxidation by Fe(III) in the presence of ophenanthroline. The formation of tris (o-phenanthroline)-Fe(II) complex (ferroin) upon diclofenac reaction was investigated. Absorbance of ferroin complex was measured at 506 nm. This method was tested on 50 mg tablets. Operating with placebos, it was found that excipients do not interfere with the determination. A good linearity was found [y = (0.0294 ± 0.0041)x + (0.1326 ± 0.0559)] with r2 = 0.9982, calibration curve showed a linear range from 5-15 μg/mL of diclofenac. The proposed method was found to be highly precise, having a relative standard deviation (CV) below 2.0 % in repeatability and intermediate precision studies. Accuracy: based on the average recovery of known amounts of drug in placebo was 98.07-101.97 % values that fall within the requirements set by USP and ANMAT (98.0-102.0 %). This method was found to be simple, rapid, specific, linear, reliable and robust, allowing the determination without preliminary extraction procedures.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Dinámica de adsorción de la Ciprofloxacina en suelos de cultivo de flores en Corrientes

Los contaminantes emergentes (CE) son un problema ambiental cada vez más notable. Su existencia en aguas residuales se debe a que las plantas de tratamiento de agua residuales no depuran este tipo de contaminante. Son considerados una amenaza al ambiente, por su persistencia y su acelerada bioacumulación en los organismos ambientales. Los fármacos son algunos de los contaminantes emergentes más encontrados en aguas residuales. La ciprofloxacina es uno de ellos y por lo tanto es importante conocer el destino ambiental de este compuesto ya que su presencia en las aguas de riego hace que puedan perdurar en el suelo y contaminar aguas subterraneas.Resultados y DiscusiónEl muestreo del suelo se realizó en la zona de Aguacero perteneciente al departamento de Mercedes, de cultivo de arroz de la capa arable (10 cm).La isotermas de adsorción se determinaron mediante ensayos de adsorción en batch. Se realizó un estudio cinético previo que muestra que el proceso de adsorción es relativamente rápido en una primera fase, alcanzando un pseudoequilibrio en pocas horas. Las isotermas se ajustaron a la forma logarítmica de la ecuación de Freundlich (R2=0,983). En general, la magnitud de la adsorción fue baja, Kfa= 0,02 ± 0,005 y 1/na=1,06 ± 0,04. La desorción es no es totalmente efectiva ya que queda un 74% retenido, indicando una irreversibilidad del proceso (Kfd= 0,08 ± 0,006 y 1/nd=1,9 ± 0,006, R2=0,992). Las isotermas de adsorción dan cuenta de una fracción ligada irreversiblemente, hecho que concuerda con la elevada histéresis que se evidencia posteriormente en el proceso de desorción.Fil: Garrafa, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Profeta, Mariela Inés. Universidad Nacional del Nordeste; ArgentinaFil: Jorge, Maria Josefa. Universidad Nacional del Nordeste; ArgentinaFil: Jorge, Lilian Cristina. Universidad Nacional del Nordeste; ArgentinaFil: Delfino, Mario Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Monzón, Celina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Romero, Jorge Marcelo. Universidad Nacional del Nordeste; ArgentinaFil: Jorge, Nelly Lidia. Universidad Nacional del Nordeste; ArgentinaXXII Congreso Argentino de Fisicoquímica y Química InorgánicaLa PlataArgentinaUniversidad Nacional de la Plata. Facultad de IngenieríaAsociación Argentina de Investigaciones Fisicoquímica

Non-targeted discovery of class-distinguishing metabolites in Argentinian pacu fish by comprehensive two-dimensional gas chromatography with principal component analysis

Pacu fish are an important source of revenue and food supply in Argentina, however the nutritional effects of raising these fish in an integrated rice-fish farming environment on the fish metabolome are still unclear. To investigate this issue, the discovery of class-distinguishing compounds between farmed and control pacu fish samples was performed by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS) followed by principal component analysis (PCA). Pacu fish muscle tissue samples were extracted and derivatized for a total of 10 farmed and 10 control fish prior to GC × GC-TOFMS analysis. The total ion current (TIC) and a diagnostic ion for sugars, mass channel (m/z) 217, data for each fish were input to PCA for the non-targeted discovery of metabolites that differentiated between the control and farmed samples. The scores revealed that the classes (farmed and control fish) separated best on PC2, with most of the variance captured on PC1 accounting for the within class variance when both the TIC and m/z 217 were used. The loadings were examined to retrieve the 50 most highly loaded analytes on PC1 and PC2 using the TIC and m/z 217 (a compiled list of the 20 most highly loaded variables on each PC for the TIC and m/z 217), which were subsequently identified and concentration ratios, [Farmed]/[Control], were calculated to determine how farming fish with rice affects metabolite concentrations in pacu fish muscle tissue. A majority of analytes are downregulated in the farmed pacu fish (39/50) with 30 of these passing a p-value threshold at the 95% confidence level while of the remaining 11 analytes that were upregulated, 4 analytes passed a p-value threshold (34 analytes total passing the p-value threshold). Many of these significant analytes were highly loaded on PC2 and are involved in important metabolic processes including protein catabolism or nucleotide metabolism and tissue repair. These PCA results provide meaningful insight into the effects of farming Argentinian pacu fish with rice fields on the fish metabolome.Fil: Monzón, Celina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Schöneich, Sonia. University of Washington; Estados UnidosFil: Synovec, Robert. University of Washington; Estados Unido

Kinetic-Spectrophotometric Method for Diclofenac Quantification

This paper introduces a kinetic-spectrophotometric method for diclofenac quantification and its application to pharmaceutical preparations. The redox reaction rate between diclofenac and KMnO4 in a strong acidic environment is determined. Plotting initial slope vs. concentration a good linearity has been found. Linear range of the essay was 5-20 ppm. The effect of temperature on the reaction rate has been studied and Ea was 21.48 kJ/mol. The proposed method was found to be highly precise, having a relative standard deviation, CV% = 1.3% for repeatability (n=10). Recovery of analyte in placebo 98.7 - 108.15%, values that fall within the requirements set by USP and ANMAT (National Drug, Food and Medical Technology Administration of Argentina). This spectrophotometric method was compared with HPLC. Statistical data show no significant difference between them. The proposed method was found to be simple, rapid, specific, allowing the determination without preliminary extraction procedures.Fil: Monzón, Celina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Sarno, María del Carmen Teresa. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Delfino, Mario Raul. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentin

Minimum variance optimized Fisher ratio analysis of comprehensive two-dimensional gas chromatography / mass spectrometry data: Study of the pacu fish metabolome

Integration of rice and fish farming, e.g., pacu fish in Argentina, has raised concern that herbicides used for rice paddies may adversely affect the fish metabolome. To study this issue, tile-based Fisher ratio (F-ratio) analysis was applied to comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) data of pacu fish raised in an integrated rice-fish farming system (farmed class) versus fish raised in tanks (tank-raised class) to discover class-distinguishing analytes. F-ratio analysis resulted in hit lists initially dominated by artifact peaks from the sample derivatization process, as well as some redundant hits. These challenges were addressed by developing an automated artifact removal algorithm and an improvement to redundant hit removal in the tile-based F-ratio analysis using a pooled farmed fish sample, either spiked with 29 metabolites (spiked class) or unspiked (i.e., the background serving as the control class). Of the 29 spiked metabolites, 23 were discovered by standard F-ratio analysis, improving to 28 discovered using control-normalized F-ratio analysis. Standard and control-normalized F-ratio hit lists initially with 185 and 246 hits, were reduced to 56 and 49 hits, respectively, after artifact removal and removing redundant hits. Next, we returned to the F-ratio analysis of the farmed fish versus the control fish. Here, we introduce a minimum variance optimized (MVO) F-ratio calculation (MVOF-ratio) that provides a comprehensive hit list ranking. The initial MVOF-ratio analysis hit list of 537 hits was reduced to 110 hits following artifact removal. Of the 110 hits, 70 expressed a concentration ratio statistically different than 1 (p < 0.05). The MVOF-ratio hit list discovered more true positives compared to the standard, tank-normalized, and farm-normalized F-ratio hit lists, providing the combination of results from the farm-normalized and tank-normalized hit lists. A majority of analytes (54 out of 70) important for normal biological functioning of pacu fish were significantly downregulated in the farmed fish, suggesting the integrated farming system may negatively impact pacu fish quality.Fil: Schöneich, Sonia. University of Washington; Estados UnidosFil: Ochoa, Grant. University of Washington; Estados UnidosFil: Monzón, Celina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Synovec, Robert. University of Washington; Estados Unido

Validation of Ninhydrin Quantitative Method for Cephalexin Generic Tablets

The Medicinal Plant of Corrientes, Argentina, elaborates, distributes and provides free 500 mg cephalexin tablets in hospitals and health care centers. HPLC-UV is the reference method to quantify this antibiotic. The spectrophotometric ninhydrin method was applied for cephalexin quantification and analytical parameters for its validation were determined. The linearity of this method was in the range 0.04-0.20 mg/mL, responding to y = 2.2338x + 0.0007, with R2 = 0.9995. The RSD% found was 0.41, indicating a good repeatability of the analytical procedure. Exactitude in recovery experience was 98.50-101.33%. Comparison using t-tests and F-test indicates that there are no significant differences between results using both methods, with a confidence level of 95%. Specificity and intermediate precision assays were satisfactory. These parameters complete the validation of ninhydrin method, according to requirements of both United States and Argentinean Pharmacopoeia, for its application on cephalexin quality control in generic tablets.Fil: Delfino, Mario Raul. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Monzón, Celina María. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste; ArgentinaFil: Sarno, María del Carmen Teresa. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Departamento de Química; Argentin