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.

[The behavior of inulin in aqueous solutions under exposure to gamma radiation]. / Issledovanie povedeniia inulina v vodnykh rastvorakh pod vozdeistviem gamma-izlucheniia.

Radiochemical transformations of inulin in aqueous solutions, in air, in the presence of inert gases, helium, nitrogen, and in nitrous oxide exposed to various doses of 60Co gamma irradiation were investigated. It was shown that interactions of inulin with OH radicals are principally responsible for radiolytic decomposition of inulin. The data on radiolysis of more simple model systems were used to make available decomposition of absorption spectra of gamma-irradiated aerated aqueous solution of inulin.