A spoonful of MOF makes ibuprofen last longer!

Researchers from the Northwestern University in Illinois, USA, have found that encapsulating ibuprofen in a sugar based metal-organic framework (MOF) makes the drug last twice as long as ibuprofen salts alone.

In 2010, the researchers inadvertently made a biocompatible MOF comprising edible sugars, namely cyclodextrins (CD-MOF). Since this discovery, the team has investigated several applications for the CD-MOF, most recently encapsulating and delivering ibuprofen.

“Unlike many other MOFs, [CD-MOF] is highly soluble in water,” said Karel Hartlieb, one of the researchers. “Water solubility can be an issue for other potential applications […] but for oral drug delivery it is a useful property.”

Traditionally, ibuprofen is delivered in free-acid form, which is poorly soluble, limiting the speed of uptake and duration of therapeutic effects. Newer formulations use various ibuprofen salts, which although improve solubility also lead to moisture susceptibility. Therefore, as CD-MOF is air and moisture stable, the researchers wondered if encapsulating ibuprofen in CD-MOF could be advantageous.

To encapsulate ibuprofen, the team developed two methods, one involving ibuprofen salt loaded onto CD-MOF and the other absorbing the free-acid form of ibuprofen into the CD-MOF.

In their experiments in mice, the team found that there were similar rates of uptake of ibuprofen from the loaded CD-MOF as control samples of ibuprofen salts alone. However, the therapeutic effects were found to last twice as long in the CD-MOF encapsulated ibuprofen without any increase in dosage.

Additionally, the air and moisture stability afforded by the sugar coating was also transferred to the ibuprofen-loaded material, which could enhance the shelf-life of the drug.