Nanostructured lipid carrier (NLC) coated with Chitosan Oligosaccharides and its potential use in ocular drug delivery system.

Abstract The objective of the present investigation was to explore the potential of the Chitosan Oligosaccharides (COS)-coated NLC (nanostructured lipid carrier) for ocular drug delivery. NLC loaded with flurbiprofen was prepared by melt-ultrasonic method and then coated with COS with a molecular weight of 3000–6000 kDa. After coating, the particles reflected spherical morphology with smooth surface under transmission electron microscope (TEM) analysis and a changed zeta potential from −0.446 mV to +20.7 mV. The ocular bioadhesion property was evaluated by Gamma scintigraphic technique, revealing that the clearance of the formulations labeled with radioactive 99 m Tc-DTPA was significantly delayed in the presence of COS, and the AUC of the COS-coated formulation had a 7.7-fold increase comparing with non-coated ones. Additionally, enhanced transcorneal penetration was achieved by using the COS coating with a corresponding apparent permeability coefficients ( P app ) which had a 2.4-fold increase comparing with the reference. Consequently, COS coating modified the properties of NLCs and presented a series of notable advantages in ophthalmic application.