Insulin containing polyethylenimine-dextran sulfate nanoparticles.

An aqueous nanoparticle delivery system has been developed which employs the oppositely charged polymers polyethylenimine (PEI) and dextran sulfate (DS) with zinc as a stabilizer. It is found that the pH of PEI solutions, the weight ratio of the two polymers, and zinc sulfate concentrations all play significant roles in controlling particle size. Spherical particles of 250 nm mean diameter were produced under optimal conditions which have a zeta potential of approximately +30 mV.