RESUMEN
Validated stability-indicating spectrophotometric and spectrofluorimetric assays (SIAMs) were developed for the determination of alfuzosin hydrochloride (ALF) in the presence of its oxidative, acid, and alkaline degradation products. Three spectrophotometric methods were suggested for the determination of ALF in the presence of its oxidative degradation product; these included the use of zero order (0D), first order (1D), and third order (3D) spectra. The absorbance was measured at 330.8 nm for (0D) method, while the amplitude of first derivative (1D) method and that of third derivative (3D) method were measured at 354.0 and 241.2 nm, respectively. The linearity ranges were 1.0-40.0 microg/ml for (0D) and (1D) methods, and 1.0-10.0 microg/ml for (3D) method. Two spectrofluorimetric methods were developed, one for determination of ALF in the presence of its oxidative degradation product and the other for its determination in the presence of its acid or alkaline degradation products. The first method was based on measuring the native fluorescence of ALF in deionized water using lamda(excitation) 325.0 nm and lamda(emission) 390.0 nm. The linearity range was 50.0-750.0 ng/ml. This method was also used to determine ALF in human plasma with the aid of a suggested solid phase extraction method. The second method was used for determination of ALF via its acid degradation product. The method was based on the reaction of fluorescamine with the primary aliphatic amine group produced on the degradation product moiety. The reaction product was determined spectrofluorimetrically using lamda(excitation) 380.0 nm and lamda(emission) 465.0 nm. The linearity range was 100.0-900.0 ng/ml. All methods were validated according to the International Conference on Harmonization (ICH) guidelines, and applied to bulk powder and pharmaceutical formulations.
Asunto(s)
Antagonistas Adrenérgicos alfa/análisis , Quinazolinas/análisis , Antagonistas Adrenérgicos alfa/sangre , Calibración , Humanos , Indicadores y Reactivos , Oxidación-Reducción , Quinazolinas/sangre , Estándares de Referencia , Solventes , Espectrometría de Fluorescencia , Espectrometría de Masa por Ionización de Electrospray , ComprimidosRESUMEN
The objectives of this study were 1. to determine the associations among circulating anti-Mullerian hormone (AMH), insulin like growth factor 1 (IGF1) and cadmium (Cd) concentrations of lactating Holstein cows at the time of superovulation and 2. to determine the effect of circulating AMH, IGF1 and Cd concentrations on the superovulatory response in Holstein dairy cows. Holstein cows (n = 30) were milked thrice daily and housed and fed in free stall barn as a separate group. All animals were synchronized for superovulation and flushed. Three blood samples for AMH, IGF1 and Cd analysis were collected prior to superovulation, at estrus and at the time of embryo collection. The concentrations of blood makers prior to superovulation were highly correlated to superovulatory response. Circulating concentrations of AMH, IGF1 prior to superovulation were negatively correlated to Cd concentrations (P < 0.05). There was no correlation between circulating concentrations of AMH and IGF1. The number of corpus luteum (r = 0.71), total embryo (r = 0.67), total transferable embryo (r = 0.51) and total grade 1 embryo (r = 0.5) were positively correlated to AMH concentrations (P < 0.05). There was a trend for negative correlation found between circulating cadmium concentrations and total grade 1 embryo yield (P < 0.1). When cows were classified into quartiles (Q) of circulating AMH concentration, number of corpus luteum, and total embryos, total transferable embryos and total grade 1 embryos yield was significantly different for AMH quartiles. The superovulatory response parameters evaluated were increased with increased AMH concentrations; particularly we observed a >2-fold difference between first and fourth AMH quartiles in total transferable embryo yield and total grade 1 embryo yield. In conclusion, circulating AMH concentration was strongly associated with superovulatory response. Measuring AMH before enrolling cows in superovulation programs will likely allow practitioners to improve numbers of embryos produced and, thereby, reduce costs per embryo produced.