RESUMEN
Conditions have been established for the determination of oxytocin by the HPLC method; the method has been validated. The results of HPLC determinations are compared with those obtained by the biological method.
Asunto(s)
Cromatografía Líquida de Alta Presión , Oxitocina/análisis , Animales , Presión Sanguínea/efectos de los fármacos , Pollos , Formas de Dosificación , Oxitocina/farmacologíaRESUMEN
Protamine sulphate, which has the property of neutralising heparin, is determined in pharmaceutical formulations using spectrophotometric (BP 1995) or biochemical methods (USP XXIII 1995). Accuracy of these methods is not very high. We applied the HPLC technique for the assay of protamine sulphate in a gel formulation. The assay was carried out on a diol-type column with a mobile phase containing 8% acetonitrile in 0.15% trifluoroacetic acid at pH 2.5. The flow rate was 1.0 ml min(-1). The results obtained show that HPLC can be used for the determination of protamine sulphate in pharmaceutical preparations. The method is rapid and more accurate than those described until now.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Antagonistas de Heparina/análisis , Preparaciones Farmacéuticas/química , Protaminas/análisis , Reproducibilidad de los ResultadosRESUMEN
Polarographic and voltammetric methods were used to study drugs of anthrone derivatives: mitoxandrone (antineoplastic), emodin (cathartic) and chrysarobin (antipsoriatic) on mercury and glassy carbon electrodes. The surface-active properties were exploited for developing a highly sensitive adsorptive stripping voltammetric method for determination of trace amounts of these compounds. Effective pre-concentration was obtained at glassy carbon electrode, with the surface species being measured via its reduction or oxidation, respectively. It was concluded that observed cathodic and anodic currents had the diffusive character. A simple, quick and accurate methods for the determination of all studied compounds in pure form and mitoxantrone in vials have been developed. The acetate buffer pH 4.6 containing 5 to 30% ethanol was used as a supporting electrolyte. The linear calibration range was 0.5 = 100 microg cm-3 on mercury and 25 - 250 ng cm-3 on glassy carbon electrode.
Asunto(s)
Antracenos/análisis , Antiinflamatorios no Esteroideos/análisis , Emodina/análisis , Mitoxantrona/análisis , Antracenos/química , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/orina , Electroquímica , Electrodos , Emodina/química , Emodina/orina , Humanos , Concentración de Iones de Hidrógeno , Mitoxantrona/química , Mitoxantrona/orina , PolarografíaRESUMEN
The polarographic reduction of flutamide was investigated by direct current polarography (DCP), alternating current polarography (ACP), normal pulse polarography (NPP) and differential pulse polarography (DPP). The supporting solution was phosphate buffer containing 5% of 95% ethanol. The reduction process at the dropping mercury electrode was diffusion controlled and irreversible. Extraction with 95% ethanol followed by polarographic reduction was selected as the basis of a method for the determination of flutamide as a pure compound and in tablets.