FTIR spectroscopic investigation and modeling of solute/polymer interactions in the hydrated state.

Attenuated total reflectance infrared spectroscopy was used to investigate possible interactions during transport of oxprenolol x HCl, bovine serum albumin, alpha-chymotrypsin, and fibrinogen through poly(acrylic acid) and its random copolymeric gels. Carbonyl and carboxylate ion peak shifts were used to identify drug/gel binding due to electrostatic and hydrogen bond interactions between the polymer carrier and the drugs tested. These findings were used to interpret the decrease in calculated diffusion coefficients of drugs diffusing through these gels and the associated hindering of drug transport. A model was developed to analyze this transport process as a function of the binding heat of the drug with the polymer.