An evaluation of a fluorometric method for determining binding parameters of drug-carrier complexes using mathematical models based on total drug concentration.

A fluorescence method for determining the mode of binding and estimating binding parameters in a model drug-carrier complex was developed using the lipopeptide antibiotic daptomycin and polyamidoamine (PAMAM) dendrimer. Mathematical simulations of model equations describing fluorescence changes induced by antibiotic-carrier binding in terms of total drug concentration were used to evaluate the sensitivity of parameter variation on binding isotherms for both one- and two-site binding models. Nonlinear regression analysis was used to estimate binding parameters and to identify pH-dependent binding models.