Design, characterization and in vitro evaluation of novel shell crosslinked poly(butylene adipate)-co-N-succinyl chitosan nanogels containing loteprednol etabonate: A new system for therapeutic effect enhancement via controlled drug delivery

This study reports on the development of a novel mucoadhesive and biocompatible shell-crosslinked nanogel system based on poly(butylene adipate) (PBA) and N-succinyl chitosan (S-Cs) by coupling reaction with a new formulation method. For this purpose, two different molecular weights of dendri-merized PBA with amine terminated functional groups were synthesized separately and characterized well by FT-IR, (HNMR)-H-1 and GPC. The PBA nanoparticles containing loteprednol etabonate (LPE) prepared by O/W emulsion technique were reacted immediately with modified carboxylated chitosan via carbodiimide chemistry. TEM photographs of the nanoparticles and crosslinked nanoparticles displayed a spherical morphology closely corresponding to the results obtained by DLS. On The other hand, biodegradability, biocompatibility and bioadhesiveness of the prepared nanoparticles were also studied. It is concluded that the core-shell structured nanogels can be used as novel ocular drug delivery systems with appropriate loading capacity for slightly water soluble LPE as an anti-inflammatory drug. (C) 2015 Elsevier Masson SAS. All rights reserved.