Effect of solution phase composition on the interaction between aqueous model solutes and polymeric container materials.

The interaction between several marker solutes and a polyolefin laminate polymer was studied in several solutions. Solutions studied included mixtures of sodium chloride and dextrose (at concentrations more less typical of i.v. administration solutions) and several actual i.v. products [lactated Ringer's injection, Dianeal, Travasol (amino acid) injection, and alcohol/dextrose injection]. The interaction properties of the candidate container material correlated well with the solute's octanol-water partition coefficient. For nonionic species, the magnitude of the container/solution interaction was independent of solution phase composition. For the ionic test solute, solution pH, which impacts the speciation of the solute, was the only solution composition variable that significantly influenced the interaction. Thus water (or a weak buffer solution) is suggested as an appropriate model solvent for use in container compatibility evaluations involving i.v.-related products.