Development of mucoadhesive and thermosensitive eyedrops to improve the ophthalmic bioavailability of ibuprofen

Topical ophthalmic formulations prepared with nanostructured lipid carriers (NLC) exhibit low bioavailability. Specific physicochemical properties of the ocular tissues, namely, temperature, pH and electrolyte composition of the pre-corneal region, can be exploited to enhance the bioavailability of colloidal nanocarriers using in situ gelling systems. The aim of this study was to enhance the ophthalmic bioavailability of NLC dispersions through the addition of a thermoresponsive polymer (Pluronic (R) F-127) and a mucoadhesive polymer (chitosan). Simulating the physiological conditions, the addition of Pluronic (R) F 127 (PF 127) caused the sol-gel transition of the colloidal dispersion upon contact with the ocular surface temperature, while the addition of chitosan (CS) led to the establishment of electrostatic interactions with the mucin present in the ocular tissues. The results also suggested that NLC-based hydrogels were biocompatible with no significant cytotoxicity observed in the Y-79 human retinoblaston-ia cell line. The addition of PF 127 and CS to NLC dispersions can enhance the bioavailability and the therapeutic efficacy of topical ophthalmic formulations. (C) 2016 Elsevier B.V. All rights reserved.