Model transport studies utilizing lecithin spherules : I. Critical evaluations of several physical models in the determination of the permeability coefficient for glucose

Abstract

1. 1. For the purpose of quantifying the transport of drugs across phospholipid membranes in complex aqueous liposome dispersions, solute release experiments were conducted with different initial boundary conditions so that sensitive tests of appropriate physical models could be made.2. 2. Simple physical models which assume monosize or multisize single membrane controlled solute transport failed to provide a reasonable agreement between the experimental data and the theory.3. 3. A systematic evaluation of all the parameters which could introduce uncertainties then revealed that the monosize-multiconcentric models are generally in satisfactory agreement with the experimental transport data. These findings suggest that these models may be used in the reliable determinations of effective bulk permeability coefficients. Calculations using the multisize-multiconcentric models and comparisons between the monosize and multisize-multiconcentric models showed that the assumption in which the particle size distribution is neglected is a good one.