Microencapsulation of Ionic Liquid by Interfacial Self-Assembly of Metal-Phenolic Network for Efficient Gastric Absorption of Oral Drug Delivery

Improving bioavailability of orally
delivered drugs is
still challenging,
as conventional drug delivery systems suffer from non-specific drug
delivery in the gastrointestinal (GI) tract and limited drug absorption
efficiency. Gastric drug delivery is even more difficult due to the
harsh microenvironment, short retention time, and physiologic barriers
in the stomach. Here, an oral drug delivery microcapsule system was
developed for gastric drug delivery, which consists of ionic liquid
(IL) as the inner carrier and metal-phenolic network (MPN) as the
microcapsule shell. The IL@MPN microcapsules are prepared by interfacial
self-assembly of FeIII and quercetin at the interface of
hydrophobic IL ([EMIM][NTf2]) and water. The formation
of MPN shell could improve the stability of IL droplets in water and
endow the system with pH-response drug release properties, while the
encapsulated IL core could efficiently load the drug and enhance the
drug tissue permeability. The IL@MPN microcapsules showed enhanced
drug absorption in the stomach after oral administration in a rat
model, where the microcapsules are disassembled in gastric acid, and
the released IL could reduce the viscosity of mucus gel and increase
the drug transport rate across endothelial cells. This work presents
a simple yet efficient strategy for oral drug delivery to the stomach.
Given the diversity and versatility of both MPN and IL, the proposed
self-assembled microcapsules could expand the toolbox of drug delivery
systems with enhanced oral drug bioavailability.