Positively Charged Amphiphilic Chitosan Derivative for the Transscleral Delivery of Rapamycin

Elsaid, Naba and Jackson, Timothy L. and Gunic, Mirza and Somavarapu, Satyanarayana (2012) Positively Charged Amphiphilic Chitosan Derivative for the Transscleral Delivery of Rapamycin. Investigative Ophthalmology & Visual Science, 53 (13). pp. 8105-8111. ISSN 1552-5783

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Official URL: http://doi.org/10.1167/iovs.12-10717

Abstract

Purpose.: We explored the potential of an amphiphilic chitosan derivative to facilitate the transscleral delivery of rapamycin, a potential multitherapeutic agent with poor water solubility. Methods.: The amphiphilic chitosan derivative, O-octanoyl-chitosan-polyethylene glycol (OChiPEG) graft copolymer, was analyzed using Fourier-transform infrared spectroscopy (FT-IR). OChiPEG micelles were prepared via the thin film method and characterized for their size using dynamic light scattering (DLS), zeta potential using laser Doppler velocimetry (LDV), morphology using transmission electron microscopy (TEM), drug entrapment efficiency (EE), and drug loading (DL) efficiency using reversed-phase high performance liquid chromatography (RP-HPLC), critical micelle concentration (CMC) using spectrofluorometry, and thermal properties using differential scanning calorimetry (DSC) and x-ray powder diffraction (XRPD). Scleral permeation and retention of rapamycin from the drug-loaded micelles were determined in porcine sclera clamped in Ussing chambers, using RP-HPLC. Results.: Conjugation of hydrophilic and hydrophobic groups to chitosan was confirmed using FT-IR. Rapamycin-loaded micelles of particle size 40.6 nm and zeta potential + 6.84 mV were prepared successfully. These carriers exhibited a high EE and DL of 85.6 and 16.3%, respectively, and a CMC of 16.6 μM. OChiPEG micelles showed a high rapamycin scleral retention (14.8 ± 0.81 μg/g) with successful transscleral permeation (5.57 ± 1.04 × 10−8 cm2·s−1). Conclusions.: Positively charged OChiPEG micelles loaded with rapamycin were prepared successfully. These showed a high scleral retention and successful permeation of rapamycin, and therefore may be useful for the topical delivery of other hydrophobic agents.

Item Type: Journal Article
Keywords: rapamycin, micelle, nanocarrier, chitosan, ocular, sclera, topical, permeation, retention, ex vivo, uveitis, age-related macular degeneration
Faculty: Faculty of Medical Science
Depositing User: Dr Naba Elsaid
Date Deposited: 20 Dec 2016 09:03
Last Modified: 16 Oct 2017 15:15
URI: http://arro.anglia.ac.uk/id/eprint/701261

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