One-Pot Synthesis and Characterization of Dapsone-Loaded Zeolitic Imidazolate Framework-8

Dapsone (DAP) is used to treat leprosy, a Neglected tropical diseases (NTDs). However, its low solubility often leads to low efficacy. In this work, ZIF-8 nanostructures loaded with DAP (DAP@ZIF-8) were successfully synthesized with suitable drug loading (DL) through a one-pot synthesis. Different parameters of the synthesis method were evaluated in terms of DL and crystal structure, and the optimized systems were characterized regarding crystallinity, morphology, molecular interactions, hydrodynamic size, and thermal stability. The results showed that the water/DMSO synthesis was effective in entrapping DAP (11.1%±2.8), providing characteristic morphology and crystal structure of ZIF-8. Particle size (193.4 ± 1.1 and 168.7 ± 2.0), polydispersity index (≤ 0.2), and zeta potential (11.4 ± 5.1 and 19.6 ± 3.13) results were consistent with nanostructured systems for both ZIF-8 and DAP@ZIF-8, respectively. Electron micrographs demonstrated the nanosized structures and their shapes, and FT-IR spectra confirmed the encapsulation of DAP and its intermolecular interactions with the organic fraction of ZIF-8. Thermal analysis confirmed the degradation profile of ZIF-8 and the molecular dispersion of DAP. In summary, the one-pot synthesis of DAP@ZIF-8 has been successfully employed to obtain an innovative system capable of loading over 10% drug, which significantly improves over other nano-based systems and represents a promising DAP delivery platform.