Pharmacokinetics and tissue distribution of anidulafungin in rats

Abstract

This study assessed the tissue distribution of anidulafungin in rats. Anidulafungin rapidly distributed into tissues, achieving peak concentrations within 30 min, and maintained levels above MICs for common pathogens over 72 h. In tissues susceptible to fungal infection (liver, lung, spleen, kidney), exposure was 9- to 12-fold higher than in plasma.

FIG. 1.

Molecular structure of [¹⁴C]anidulafungin, in which the position of the ¹⁴C radiolabel is indicated by an asterisk.

FIG. 2.

Study 1. Mean (n = 3) concentration-versus-time profile for anidulafungin (parent drug) in plasma (ng/ml) and in key tissues (ng/g) following a single intravenous bolus dose of 5 mg/kg [¹⁴C]anidulafungin in male F344 rats.

FIG. 3.

Study 1. Tissue/plasma ratio of AUC_0-∞ of anidulafungin (parent drug) following a single intravenous bolus dose of 5 mg/kg [¹⁴C]anidulafungin in male F344 rats.

FIG. 4.

Study 1. Mean (n = 3) concentration-versus-time profile of drug-derived radioactivity (ng eq/g) in plasma and key tissues following a single intravenous bolus dose of 5 mg/kg [¹⁴C]anidulafungin in male F344 rats.