RESUMEN
A method for the analysis of two-component mixtures of cephalothin and cefoxitin using zero-crossing first-derivative spectrophotometry is described. This technique permits the quantification of these drugs with closely overlapping spectral bands without any separation step. Linear calibration graphs of first-derivative values at 235.00 and 236.75 nm for cephalothin and cefoxitin, respectively, with negligible intercepts were obtained versus concentration in the range 4.0-32.0 micrograms ml-1 for both antibiotics. This paper presents a systematic examination of the experimental data by applying an exhaustive statistical analysis to demonstrate the validity of the method. The results of the determination of these antibiotics in mixtures of injectable dosage forms are also presented, together with their determinations in physiological serum and glucosed physiological serum.
Asunto(s)
Quimioterapia Combinada/análisis , Calibración , Cefoxitina/análisis , Cefoxitina/sangre , Cefoxitina/química , Cefalosporinas/análisis , Cefalosporinas/sangre , Cefalosporinas/química , Cefalotina/análisis , Cefalotina/sangre , Cefalotina/química , Cefamicinas/análisis , Cefamicinas/sangre , Cefamicinas/química , Quimioterapia Combinada/química , Humanos , Concentración de Iones de Hidrógeno , Indicadores y Reactivos , Infusiones Intravenosas , Soluciones , Espectrofotometría UltravioletaRESUMEN
Two-component mixtures of cefsulodin and clavulanic acid were analysed by a first-derivative spectrophotometric method using a zero-crossing technique of measurement. The relative ease offered by this derivative technique for the quantification of these drugs, with closely overlapping spectral bands, was clearly demonstrated. As the absorption band of clavulanic acid closely overlaps with that of cefsulodin, both direct and derivative spectrophotometric methods have been investigated and evaluated by an exhaustive statistical analysis of the experimental data. The first-derivative spectrophotometric method was found to be more rapid, accurate and reproducible. The procedure does not require any separation step. The calibration graphs were linear in the range 2.0-56.0 micrograms ml-1 for cefsulodin and 2.0-28.0 micrograms ml-1 for clavulanic acid. The lower detection limits of cefsulodin and clavulinic acid (P 0.05 level) were calculated to be 0.16 and 0.24 microgram ml-1, respectively. Mixtures of cefsulodin and clavulanic acid in ratios of 1:4-7:2 were satisfactorily resolved. Both components were also determined in physiological solutions used to prepare intravenous infusions of these antibiotics.
Asunto(s)
Antibacterianos/análisis , Cefsulodina/análisis , Ácidos Clavulánicos/análisis , Antibacterianos/química , Calibración , Cefsulodina/química , Ácido Clavulánico , Ácidos Clavulánicos/química , Simulación por Computador , Interpretación Estadística de Datos , Concentración de Iones de Hidrógeno , Infusiones Intravenosas , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrofotometría UltravioletaRESUMEN
A fluorimetric method has been developed for the quantitative analysis of cefuroxime, based upon the formation of a fluorescent derivative formed by alkaline hydrolysis with 1.0 M sodium hydroxide and heating at 100 degrees C for 60 min. The fluorescent product gave excitation and emission maxima at 380 and 436 nm, respectively. The method was performed in aqueous solution adjusted to pH 10.5 by addition of phosphate buffer solution. The calibration curve was found to be linear in the range of concentrations 0.050-1.70 micrograms ml-1. The lower limit of detection was 1.0 x 10(-2) micrograms ml-1. The method was applied to authentic pharmaceutical preparations containing cefuroxime sodium or cefuroxime axetil, the 1-(acetyloxy) ethyl ester of the drug, and was found to be satisfactory. Cefuroxime sodium was also determined in physiological solutions used to prepare intravenous infusions of this antibiotic.
Asunto(s)
Cefuroxima/análisis , Hidrólisis , Indicadores y Reactivos , Infusiones Intravenosas , Soluciones , Espectrometría de Fluorescencia , Suspensiones , TemperaturaRESUMEN
A fluorescence method involving sample pre-treatment is investigated concerning the determination of cefoxitin. A fluorescent product is formed when samples containing cefoxitin are subjected to alkaline hydrolysis with 1.0M sodium hydroxide and heated for 60 min at 90 degrees . The fluorescence is measured in ethanol/water medium (50% v/v) at approximately pH 2.0 provided by adding of 0.1M hydrochloric acid. The fluorescence excitation and emission maxima were 317 and 400 nm, respectively. The quantitative range is between 0.020 and 1.40 mug/ml. A detection limit of 2 x 10(-3) mug/ml was found. The proposed method has been applied to the determination of cefoxitin in commercial injections, saline and glucosed physiological serum.
RESUMEN
The functioning of the Intensive Care Units has permitted a better study and treatment of the arrhythmias which complicate the acute phase of myocardial infarction. 1,100 charts of patients admitted to the Coronary Unit of the National Institute of Cardiology of Mexico were reviewed. Acute myocardial infarction was demonstrated in 819 of them by the usual methods. The frequency and characteristics of the following bradiarrhythmias were studied: sinus bradicardia, sinus stoppage, seno-atrial block, migration of the atrial pacing, union rhythm and slow ventricular tachycardia. Sinus bradicardia was presented in 23.7% of the infarctions, sinus stoppage in 2.4%, migration of the atrial pacing in 9.4%, nodal rhythm in 7.2% and slow ventricular tachycardia in 7.8%. Bradiarrhythmias, generally considered as "lesser" arrhythmias, favor the appearance of lethal arrhythmias, regardless of the degree of mechanical failure, and thus should be treated actively.