UV-photocrosslinking of inulin derivatives to produce hydrogels for drug delivery application.

In this work, INU, a natural polysaccharide, has been chemically modified in order to obtain new photocrosslinkable derivatives. To reach this goal, INU has been derivatized with MA thus obtaining four samples (INU-MA derivatives) as a function of the temperature and time of reaction. An aqueous solution of the derivative INU-MA1 was irradiated by using a UV lamp with an emission range from 250 to 364 nm and without using photoinitiators. The obtained hydrogel showed a remarkable water affinity but it underwent a partial degradation in simulated gastric fluid. To overcome this drawback, INU-MA1 was derivatized with SA thus obtaining the INU-MA1-SA derivative designed to produce a hydrogel showing a low swelling and an increased chemical stability in acidic medium. Ibuprofen, as a model drug, was loaded by soaking into INU-MA1 and INU-MA1-SA hydrogels and its release from these matrices was evaluated in simulated gastrointestinal fluids. INU-MA1 hydrogel showed the ability to quickly release the entrapped drug thus indicating its potential as a matrix for an oral formulation. INU-MA1-SA hydrogel showed a pH-responsive drug delivery. Therefore it is a promising candidate for controlled drug release in the intestinal tract.