Fe(III)-Based Layered Double Hydroxides Carrying Model Naproxenate Anions:Compositional and Structural Aspects

摘要

In this work,Al cation was gradually replaced by Fe~(III)in the composition of Layered Double Hydroxides(LDH)and systematically investigated for LDH application as drug carriers,ultimate aiming to improve their biointegration.The incorporation of Fe~(III)into LDH layers,as well the intercalation of organic anions in the iron-based materials,is challenging.Several studies approach the intercalation of non-steroidal antiinflammatory drugs such as anionic naproxen(NAP)into Al-LDH.Thus,NAP was applied here as a model drug for the study of compositional and structural aspects of novel FeIII-LDH carriers envisaging to shed light on the intercalation of other carboxylate drugs into these materials.LDH of general [M2FeyAl_((1-y))(OH)6]A~(n-)compositions(M~(II)=Mg or Zn;A~(n-)=anion of charge n)were investigated using two synthetic methods for NAP intercalation.Full X-ray diffraction profile refinement and a crystal-geometrical reasoning were used to strengthen the results interpretation.Unlike coprecipitation,in which probably NAP complexation with FeIII hinders LDH-NAP self-assembling,topotactic ion exchange demonstrated to be a potential approach.