INTERACTIONS BETWEEN GELATIN AND AMPHIPHILIC SUBSTANCES

Interactions between gelatin and different surfactants in aqueous syst ems are investigated by surface tension measurement, polarimetry, visc ometry and transmission electron microscopy. As anionic surfactant the pharmaceutical drug fenoprofen sodium is used while polyoxyethylene c etylethers are used as nonionics. Fenoprofen obstructs the renaturatio n of gelatin and decreases the viscosity of a gelatin solution. The no nionic surfactants promote the helix formation and increase the viscos ity. As an explanation a stepwise association of surfactant molecules is proposed in case of fenoprofen sodium while the nonionics interact as complete micelles with the polymer and lead to a cross-linking of t he gelatin molecules.