CONTROLLED RELEASE OF INDOMETHACIN USING MIL-101(Fe): A PROMISING METAL-ORGANIC FRAMEWORK FOR DRUG DELIVERY

Abstract

The use of metal–organic frameworks (MOFs) as drug carriers offers promising potential for controlled drug delivery systems. MIL-101(Fe) is a stable and non- toxic MOF with outstanding pore capacity and wide pore windows that can accommodate and allow entry to a large number of drug molecules. However, it has been hugely underutilized in the development of drug delivery systems. This study investigates the suitability of highly porous MIL-101(Fe) as a carrier for the non-steroidal anti-inflammatory drug indomethacin, thereby reducing potential side effects, dosage, and peak plasma concentration, while increasing its half-life. MIL-101(Fe) was synthesized using a modified solvothermal technique to enhance purity, and then loaded with indomethacin by suspending 25 mg of the MOF in 25 ml of a 500 mg l-1 ethanolic indomethacin solution. The drug release behavior was studied by suspending 5 mg of the loaded MOF in phosphate-buffered saline (PBS) at pH 7.4 and hydrochloric acid (HCl) solution at pH 4.0 at 37 ℃ to simulate intestinal and mildly acidic gastric environments, respectively. The MOF structure was confirmed by powder X-ray diffractometry and Fourier Transform Infrared Spectroscopy. A high drug loading capacity of ~27% was observed within 24 hours, with the help of UV-visible spectrophotometry-assisted calculations. The release studies revealed a sustained release profile with no significant initial burst. Release was evaluated using UV- visible spectrophotometry at 317 nm. After 48 hours, ~49.8% of the encapsulated drug was released in PBS, while only ~7.1% was released in HCl, indicating a pH-sensitive release behavior. These findings demonstrate that MIL-101(Fe) is a promising candidate for oral delivery of indomethacin, offering slow and targeted release in the intestinal environment while minimizing premature drug release in the stomach and associated side effects. Further research on modifying the MOF structure and implementing post-synthetic modifications may enhance the MOF’s affinity to indomethacin, thereby increasing its loading capacity and release efficiency. More research is needed to determine whether this MOF can be used as a drug delivery vehicle for additional medications, as well as to minimize MOF degradation under highly acidic conditions within the stomach.