Comparative evaluation of natural and acid-modified layered mineral materials as rimifon-carriers using UV/VIS, FTIR, and equilibrium sorption study

The encapsulation of rimifon on natural (NZ) and acid-modified (AMZ) zeolites was investigated by UV/VIS, FTIR, and equilibrium sorption studies in aqueous medium. The UV/VIS and FTIR spectral investigations provided data on the nature and characteristics of the drug–zeolite complexes. The probable host–guest interactions during rimifon encapsulation in AMZ include van der Waals interactions, as well as H-bonds established between the O-atom from the carbonyl (>C=O) group and N-pyridine/N-hydrazine atoms in rimifon and zeolite OH-groups. The maximum experimental equilibrium sorption capacity of AMZ (qmax = 7.17 mg/g) was approximately 24 times higher than that of NZ. Baudu and Fritz–Schlunder isotherms almost overlapped and seemed to be the best-fitting models with regard to the experimental equilibrium data of rimifon sorption on AMZ. The unique properties of AMZ and the established high extend of rimifon encapsulation proved the possibility of its successful application as rimifon-carrier for environmental and medical purposes. Subjects: Analytical Chemistry; Environmental Chemistry; Health and Social Care; Medicinal & Pharmaceutical Chemistry