RESUMEN
The stability of milrinone in 0.45% and 0.9% sodium chloride injections and in 5% dextrose injection in glass and plastic containers was studied. Admixtures containing milrinone 0.2 mg/mL were prepared in three 500-mL glass containers, three 500-mL polyethylpolypropyl copolymer plastic containers, and three 1-L flexible plastic containers of each solution. Milrinone content was determined by high-performance liquid chromatography at intervals during 72 hours of storage at room temperature; one sample of each solution and container type was protected from light. Duplicate assays of each sample were performed, and samples were observed for visual and pH changes. In all samples milrinone concentrations were more than 97% of the initial concentration. No changes in pH or appearance occurred. Milrinone at a concentration of 0.2 mg/mL is stable for 72 hours at room temperature in 0.45% and 0.9% sodium chloride injections and in 5% dextrose injection in glass or plastic containers.
Asunto(s)
Piridonas/análisis , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Glucosa/análisis , Concentración de Iones de Hidrógeno , Milrinona , Cloruro de Sodio/análisis , SolucionesRESUMEN
An automated colorimetric method is described for the measurement of certain catecholamine drugs, such as isoproterenol and epinephrine, in sample solutions derived from 2 metered doses delivered from the mouthpiece of aerosol inhalation units. The procedure, applicable to the expressed product, involves oxidizing the catecholamine with potassium ferricyanide at pH 6 to produce an aminochrome. This method is similar to the well known trihydroxyindole reaction procedure but differs in that the formed aminochrome is measured spectrophotometrically at 495 nm instead of being further derivatized by alkaline rearrangement to the trihydroxyindole species followed by either spectrophotometric or fluorometric measurement.
Asunto(s)
Catecolaminas/análisis , Aerosoles , Autoanálisis , Catecolaminas/administración & dosificación , Epinefrina/análisis , Indicadores y Reactivos , Isoproterenol/análisis , Espectrometría de FluorescenciaRESUMEN
A new ceramic form of hydroxylapatite and enamel were found to behave similarly in regard to their acid dissolution behavior in the presence and absence of topically applied fluoride. Discrepancies between the two materials can be explained by morphological differences between the rough enamel and smooth ceramic particles.
Asunto(s)
Solubilidad del Esmalte Dental , Esmalte Dental/metabolismo , Fluoruros Tópicos , Hidroxiapatitas , Cerámica , Fenómenos Químicos , Química Física , Esmalte Dental/ultraestructura , Solubilidad del Esmalte Dental/efectos de los fármacos , Fluoruros Tópicos/metabolismo , Fluoruros Tópicos/farmacología , Humanos , Fluoruro de Sodio/farmacología , Solubilidad , Propiedades de SuperficieRESUMEN
A direct spectrophotometric method for the quantitative determination of sulfathiazole and the total pyrimidyl sulfonamide content in a mixture containing sulfadiazine and sulfamerazine is reported. This three-component system was readily reduced to the problem of a simple two-component system analysis. Based on dual isoabsorptive wavelength spectroscopy, simultaneous equations were developed that required absorbance measurements at only two selected wavelengths both isoabsorptive. The location of the isoabsorptive wavelengths was dependent on the pH of the solvent medium, and 0.1 M HCl gave the best results. The validity of the derived equations was demonstrated in a recovery study involving synthetic mixtures containing varying quantities of the three sulfonamides. The recovery was linear over a wide concentration range, and the precision of the method was about 1%.
Asunto(s)
Sulfadiazina , Sulfamerazina , Sulfatiazoles/análisis , Métodos , Espectrofotometría Ultravioleta , Sulfadiazina/análisis , Sulfamerazina/análisis , Comprimidos/análisisRESUMEN
A sensitive and specific method is described for the determination of 17-monochloroacetylajmaline (I) and its metabolite, ajmaline (II), in plasma. Method specificity is accomplished by combining an ion-pair extraction with chromatography followed by development and utilization of reaction product fluorescence of the isolated species on silica gel. Recovery of I and II added to plasma or water averaged 70%. The major loss in the assay resulted during a solvent evaporation step and was reproducible over the concentration interval studied. The limit of detectability for I is 0.06 mu-g/2 ml of plasma. The method was used to determine plasma levels of I and II in the dog following a dose of 10 mg/kg iv of I.