Amphotericin B (AmB) is a widely used polyene antibiotic to treat systemic fungal infections, and the absorption process of AmB is related with biomembrane closely. In this work, the interaction between AmB and cholesterol (an important biomembrane in cell membrane) was investigated in terms of the mean surface area per molecule (A), elastic modulus (C_S^－1), surface excess Gibbs energy (ΔG_ex) and interaction parameter (α) on the basis of surface pressure-area (π-A) isotherms. The results indicate that the compressibility, stability and thermodynamic characteristics of binary mixtures of cholesterol/AmB show a marked dependence on the mole faction of AmB and the surface pressure, which has been further proved by the interaction parameter α.

Key words: amphotericin B, monolayer, elastic modulus, excess Gibbs energy, interaction parameter