A method is described whereby an extraction profile is used to determine solute/polymer interaction properties (total pool and partition coefficient) which can be used to estimate the level to which an extractable component of the polymer can accumulate in solution. The extraction profile is obtained by measuring the equilibrium solution concentration of the extractable for varying amounts of polymer extracted. Either the interaction properties obtained from these data or the profiles themselves are used to estimate the maximal equilibrium solution accumulation of the extractable. The method is used to estimate the levels to which several extractables from a rubber material used in the pharmaceutical industry will accumulate in solution. The measured properties produce estimated accumulations which match experimental observations well.