Polymeric cyclodextrin-based nanoparticles: synthesis, characterization and sorption properties of three selected pharmaceutically active ingredients

The reaction of three cyclodextrins, namely α-, β- and γ-cyclodextrins, with toluene-2,4-diisocyanate yields water-insoluble polymers that in the case of the α- and β-derivatives self-assemble in aqueous and ethanolic solutions as polydisperse polymeric nanoparticles. The so-produced nanomaterials have been characterized by means of scanning electron microscopy, BET (Brunauer, Emmett and Teller) nitrogen adsorption technique and ζ-potential measurements. The interactions of these nanoparticles with three selected pharmaceutically active ingredients (levofloxacin, aspirin and acetaminophen) have been studied in aqueous solution. It is demonstrated that in all cases the interactions of the studied drugs with the produced polymeric nanomaterials follow the well-established Freundlich model suggesting that the polymers act as heterogeneous sorbents in aqueous phase. It is demonstrated that the β-cyclodextrin-based polymer exhibits the highest sorption capacity for all three pharmaceuticals compared to the α- and γ-analogues, with a higher affinity for aspirin. The influence of the chemical structure of the guest molecule on the interactions of the produced nanoparticulate polymers is discussed.