Magnetically responsive microspheres for the pulsed delivery of insulin

This paper describes a new formulation for triggered delivery of insulin which consisted of magnetic particles dispersed in alginate spheres. When magnetic field was applied to that system, the release rate of insulin was about 50 times higher than in the absence of magnetic field. The influence of oscillating magnetic field was tested, in the same experimental conditions, on polyethylenimine cross-linked alginate spheres. In that case, the pulsed delivery of insulin occurred not immediately but during the period just after applying the magnetic field. The proposed magnetically responsive alginate spheres open new perspectives for the rhythmically delivery of peptides.