RESUMEN
An accurate, precise, and sensitive high-performance liquid chromatography (HPLC) assay was developed for the determination of atenolol in human plasma samples to compare the bioavailability of 2 atenolol tablet (50 mg) formulations in 24 volunteers of both sexes. The study had an open, randomized, 2-period crossover design with a 1-week washout period. Plasma samples were obtained over a 24-hour interval. Atenolol concentrations were analyzed by combined reversed phase liquid chromatography and fluorescence detection (lambda(EX) = 258 nm, lambda(EM) = 300 nm). From the atenolol plasma concentration versus time curves, the following pharmacokinetic parameters were obtained: AUC(0-24h), AUC(0- infinity ), and C(max). The geometric mean of test/reference 50-mg tablets individual percent ratio was 102.2% for AUC(0-24h), and 101.6% for C(max). The 90% confidence intervals (CI) were 100.2% to 105.4% and 100.9% to 103.5%, respectively. Since the 90% CI for both C(max) and AUC(0-24h) were within the 80% to 125% interval proposed by the Food and Drug Administration, it was concluded that atenolol (50-mg tablets) test formulation was bioequivalent to the reference formulation, with regard to both the rate and extent of absorption.
Asunto(s)
Antihipertensivos/sangre , Atenolol/sangre , Cromatografía Líquida de Alta Presión/métodos , Disponibilidad Biológica , Química Farmacéutica , Estabilidad de Medicamentos , Femenino , Humanos , Masculino , Control de Calidad , Estándares de Referencia , Sensibilidad y Especificidad , Comprimidos , Equivalencia TerapéuticaRESUMEN
A simple, fast, sensitive and selective solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method for the quantitative analysis of ampicillin (CAS 69-53-4) in human plasma was developed using amoxicillin as internal standard, and sample extraction by solid-phase extraction (SPE). Extracts were separated by reversed-phase C18 with aqueous mobile phase (acetonitrile, 80:20, v/v) with 0.1% formic acid. The method was validated and successfully applied in a bioequivalence study of capsules 500 mg of ampicillin. Using a short running time of 2.5 min, the lower limit of quantification (LLOQ) for obtained ampicillin was 0.1 microg/ml for a plasma sample of 250 microl and a recovery of 94.38% +/- 4.05. Bioequivalence between the products was determined by calculating 90% confidence intervals (CI) for the ratio of Cmax, AUC0-t and AUC0-inf values for the test and reference products, which were within the 0.80-1.25 interval proposed by FDA and EMEA. It is concluded that the two formulations are bioequivalent in their rate and extent of absorption, and thus, may be used interchangeably.