Iron(III)-Tricarboxylate Metal-Orgonic Framework (MOF) as drug carrier in the loading of codeine

Metal-organic frameworks (MOFs) constructed using Fe (III) ion and benzene-1,3,5-tricarboxylate ligand by a solvent-based method and formulated as [Fe3(btc)2] is herein reported. The synthesized compound was characterized by powder X-ray diffraction (PXRD), Braunuer Emmet Teller (BET) analysis, and Scanning Electron Microscope (SEM). The diffraction pattern of the drug-loaded MOFs showed the appearance of new peaks and a decrease in the intensity of some peaks. The BET pore volume of synthesized [Fe3(btc)2] and [Fe3(btc)2]@COD` were 0.290cc g−1 and 0.059 cc g−1 respectively while the BET surface area of synthesized [Fe3(btc)2] and [Fe3(btc)2]@COD` were 849.63 m2 g−1 and 203.4 m2 g−1 respectively confirming the incorporation of codeine into [Fe3(btc)2], the BET analysis confirmed that the codeine was loaded into the pore cavity of [Fe3(btc)2]. The [Fe3(btc)2] was observed to encapsulate 249 mg of codeine drug per 200 mg of [Fe3(btc)2], with a loading efficiency of 91%. Binding energy calculations (DFT) revealed strong interactions, with HOMO localized on codeine and LUMO on trimesic acid, reducing the HOMO-LUMO gap from 5.3 eV (MOF) to 4.19 eV (MOF-Codeine). Molecular dynamics (100 ns) showed stable codeine binding via hydrogen bonding and π-cation interactions, enhanced by water-mediated effects. Molecular docking confirmed stronger binding affinity for codeine (Glide score: -4.349 kcal/mol) compared to nitrogen (-2.632 kcal/mol), attributed to hydrogen bonding and π-cation interactions. These results highlight [Fe₃(btc)₂] as a promising drug delivery system with high loading capacity and stable host-guest interactions.