Biodisponibilidade comparativa de duas formulações de losartan em voluntarios humanos sadios apos administração de dose unica / Comparative bioavailability of two losartan formulations in healthy human volunteers after a single dose administration

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This dissertation focus in the evaluation of the bioavailability of two formulations of potassium losartan immediate release tablet 50mg (Losartan from Laboratórios Cristália Ltd., Brazil, as a test formulation and Cozaar® from Merck Sharp &Dohme Farmacêutica Ltd., Brazil as a reference formulation). The bioequivalence study was conducted using an open, randomized, in a two-period crossover design and a one week washout period. Plasma samples were obtained over a 24hour interval. The concentrations of losartan and its active metabolite losartan acid were analyzed by combined reversed phase liquid chromatography and tandem mass spectrometry (LC-MS-MS) with negative ion electrospray ionization using a selected ion monitoring method. From the losartan and losartan acid plasma concentrations vs. time curves the following pharmacokinetic parameters were obtained: AUClast, AUC0-inf and Cmax. Results: the geometric mean and respective 90% confidence interval (CI) of Losartan / Cozaar® losartan percent ratios were 92.9% (82.2 - 105.0%) for Cmax, 99.0 (92.5 - 105.9%) for AUClast, and 99.1% (92.7 - 105.8%) for AUC0-M. Furthermore, the geometric mean and respective 90% confidence interval (CI) of Losartan / Cozaar® losartan acid percent ratios were 98.5% (91.5 - 106.0%) for Cmax, 97.9 (93.3 - 102.7%) for AUClast, and 98.1% (93.6 -102.9%) for AUC0 -inf. Since the 90% CI for Cmax, AUClast and AUC0-M were within the 80-125% interval proposed by the US-Food and Drug Administration. It was concluded that the potassium losartan immediate release 50 mg tablet was bioequivalent to the Cozaar® immediate release 50 mg tablet, according to both the rate and extent of absorption. Since there were no significant differences in the bioequivalence assessed by either losartan or losartan acid, future bioequivalence studies on losartan may be performed by quantifying losartan alone as the parent compound is more discriminative

ASSUNTO(S)

lc-ms-ms espectrometria de massa bioequivalencia mass spectrometry valsartan valsartan bioequivalence

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