Bioequivalence Study of Two Letrozole Tablet Formulations

Abstract

The study was conducted in order to compare the bioavailability of two tablet formulations containing letrozole 2.5 mg (CAS 112809-51-5). Twenty healthy subjects were enrolled in a single-centre, bioequivalence, randomised, single-dose, open-label, two-way crossover study, performed under fasting conditions with a minimum washout period of 21 days. Plasma samples were collected up to 240 h post-dosing. Letrozole levels were determined by reverse liquid chromatography and detected by tandem mass spectrometry detection, LC/MS/MS method. Pharmacokinetic parameters used for bioequivalence assessment, area under the concentration-time curve from time zero to time of last non-zero concentration (AUC_0–t) and from time zero to infinitive (AUC_0–inf) and maximum observed concentration (C_max), were determined from the letrozole concentration data using non-compartmental analysis.

The 90% confidence intervals obtained by analysis of variance were 90% geometric confidence intervals of the ratio (A/B) of least-squares means from the analysis of variance (ANOVA) of the In-transformed AUC_0–t, and C_max was within 80% to 125%. Bioequivalence between formulations was concluded both in terms of rate and extent of absorption.

Key words

Anticancer agents - CAS 112809-51-5 - Letrozole, bioequivalence

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