Pharmacokinetics and Relative Bioavailability Evaluation of Linezolid Suspension and Tablet Formulations

Abstract

The oral liquid formulations poses an alternative way in providing medications to pediatric patients, geriatric patients, patients with feeding tubes, and patients who cannot swallow solid dosage forms. This study was conducted to evaluate the pharmacokinetics (PKs) and relative bioavailability of suspension (reference) and tablet (test) formulations of Linezolid (LZD). In vivo study was established according to a single-center, randomized, single-dose, laboratory-blinded, 2 Way, Cross-Over Study with a washout period of 1-week. Under fasting conditions, 28 healthy Egyptian male volunteers were randomly allocated to receive a single oral dose of either 30 ml LZD or 1 tablet (600 mg LZD) of marketed suspension and tablet formulations. Plasma samples were obtained over a 48-h interval and analyzed for LZD by reversed phase liquid chromatography with ultraviolet detection. The 90% confidence intervals for the ratio of log transformed values of C_max, AUC_0-t, and AUC_t-∞ of the two treatments were within the acceptable range (0.8–1.25) for bioequivalence. From PK perspectives, in this small study in healthy Egyptian adult male volunteers, a single 600 mg dose of the tablet formulation demonstrated comparable rate and extent of absorption to a single 600 mg dose of the suspension formulation based on the US FDA’s regulatory definition. No adverse events occurred or were reported after a single 600 mg LZD and both formulations were well tolerated.

Key words

linezolid - HPLC - human plasma - pharmacokinetics - bioequivalence

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