Porous clay heterostructures: A new inorganic host for 5-fluorouracil encapsulation

This study proposed a new inorganic host for drug encapsulation. Porous clay heterostructure (PCH), synthesized using modified montmorillonite with hexadecyltrimethylammonium bromide, was used as host material and 5-fluorouracil (5-FU) as guest drug. Drug encapsulation within PCH in different conditions (soaking time, temperature and pH value) was investigated. Possible interactions of 5-FU with PCH were pointed out using different characterization methods like spectroscopic techniques (FT-IR, UV-vis, XPS), thermogravimetrical and BET analysis. The obtained results suggested that PCH host exhibits a high drug encapsulation efficiency which was influenced by factors like soaking time and pH value. PCH zeta potential value was strongly influenced by pH value. The PCH zeta potential significantly varies at acid pH, while a pH value higher than 7 provides a less variation. UV-vis analysis showed that after 30 min PCH host registered a maximum encapsulation efficiency value (44%) at room temperature using an incubation solution with a pH of 11. The soaking temperature does not substantially affect the loading of drug in PCH host. Thermogravimetrical analysis highlighted that drug encapsulation efficiency of PCH was mainly influenced by pH values. BET results confirmed the PCH synthesis and drug loading capacity.