Combined poly(isobutylcyanoacrylate) and cyclodextrins nanoparticles for enhancing the encapsulation of lipophilic drugs

Purpose. The aim of this study was to prepare and characterize nano-particulate systems constituted of poly(isobutylcyanoacrylate) and cyclodextrins and intended for increasing the loading of the particles with lipophilic substances. Progesterone was used as a model substance. Methods. Nanoparticles were prepared by polymerization of isobutylcyanoacrylate in presence of cyclodextrins or progesterone/hydroxypropyl-beta-cyclodextrin complex. Particle size, zeta potential, cyclodextrin and progesterone loading of the particles were determined. Results. Nanoparticles could be easily prepared in presence of cyclodextrins. An increase in hydroxypropyl-beta-cyclodextrin concentration resulted in small nanoparticles (less than 50 nm). It was found that large amounts of cyclodextrins remained associated to the particles, resulting in a 50 fold increase in progesterone loading compared to nanoparticles prepared in absence of cyclodextrins. Conclusions. The poly(isobutylcyanoacrylate)-cyclodextrin nanoparticles were characterized by the presence of many lipophilic sites belonging to the cyclodextrins which were firmly anchored to the structure of the particles. Therefore, this new type of nanoparticles offers probably an opportunity for increasing the loading of nanoparticles with various lipophilic drugs.