Ibuprofen-loaded liposomes: Insights from spin-label Electron Paramagnetic Resonance spectroscopy.
Aloi E., Bartucci R.
Ibuprofen (IBP) is a poorly water-soluble, nonsteroidal anti-inflammatory drug widely used for pain treatment. Its solubility and bioavailability can increase in lipid-based formulations used for drug delivery. Our spin-label EPR study reveals that IBP incorporated in multi-walled liposomes locates at the polar/apolar interface and stabilizes the lamellar fluid state. The drug downshifts the main-transition temperature and markedly reduces the transition cooperativity and suppresses the pre-transition in a concentration-dependent manner. IBP does not affect the chain flexibility in the gel and liquid-crystalline phases, whereas it decreases the polar head-groups packing. Non-specific interactions drive the drug effects on the lipid bilayers.