In vitro diffusion studies of some polyene antibiotics with a three-phase partition apparatus

The behaviour of a series of new polyene antibiotics derived from partricin A was studied using a suitable apparatus, consisting of a triphasic water/oil/water system for the in vitro evaluation of the diffusion characteristics. The transport rate constant from the donor aqueous phase to the receiving aqueous phase, through the oil phase, was found to be directly proportional to the concentration of the test product in the donor aqueous phase, inversely proportional to the pH values of the aqueous phases and directly proportional to the oil/water partition coefficient of the various polyenes considered. Information was thus obtained about the possible in vivo behaviour of the series of products considered, which would prove helpful in planning furthermore extensive and more thorough investigations on a restricted number of molecules.