Uptake and release of Dexamethasone using pH-responsive poly(2-hydroxyethyl methacrylate-co-2-(diisopropylamino)ethyl methacrylate) hydrogels for potential use in ocular drug delivery

PAULA A. FACCIA; PAULA A. FACCIA; JAVIER I. AMALVY; JAVIER I. AMALVY; FRANCISCO M. PARDINI; FRANCISCO M. PARDINI

JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY

EDITIONS SANTE

Año: 2019 vol. 51 p. 45 - 54

1773-2247

pH-responsive hydrogels prepared bycopolymerization between 2-hydroxyethyl methacrylate (HEMA) and2-(diisopropylamino)ethyl methacrylate (DPA) appear to be a promising systemfor controlling Dexamethasone 21-disodium phosphate (DXP) release behaviors for ophthalmological treatments. Theincorporation and subsequent release of DXP by HEMA-DPA copolymers have been evaluatedin different pH mediums and in vitro conditions. Optical and morphologicalcharacteristics, as well as wettability, drug-matrix interactions and drug-releaseproperties, were assessed. Drug incorporation was maximum at pH 6.5 and at an initialdrug concentration of 200 mg/L. Additionally, increasing the DPA content andcross-linker ratio increased the amount of loaded DXP. The amount of DXPreleased was approximately 70 %, and the entire release process took 20 to 40hours. Moreover, the copolymers showed changes in the release rate in responseto small pH variations (between 7.0 and 7.8). Additionally, DXP release by the copolymers far exceeded the estimatedconcentration of the drug absorbed in the eyes by drop administration