Abstract
Purpose:
Cyclosporine (CsA) is an immunosuppressive agent that has shown a strong immunosuppressive effect in a variety of animal models of transplantation and experimental autoimmune uveitis and uveoretinitis after systemic adminstration. However, it has limited ocular therapeutic effects due to its poor permeability across ocular biological barriers while topical application. The purpose of this study is to develop positive charged nanoemulsion for enhancing the permeability of CsA across ocular biological barriers to treat uveitis after ocular topical application.
Methods:
A series of positive charged nanoemulsions were prepared.. The size and zeta potential of the nanogels are studied by Malvin laser particle size analyzer. The release kinetics of CsA from the nanoemulsion were measured and calculated using bulk-equilibrium reverse dialysis bag technique. Ocular irritation test was performed in Japan White rabbits. The ocular distribution and pharmacokinetics of the CsA levels in the cornea, sclera, conjunctiva, aqueous humor, vitreous and whole blood were assessed after ocular single dose and loading dose topical application, resptively.
Results:
Laser particle size analyzer measurement demonstrate that the sizes of the nanoemulsions are around 29-51 nm at room temperature, and the zeta potential are +15-31mV. The accumulative release of CsA from the nanoemulsions were more than 80% within 2 hours. Ocular pharmacokinetics of the nanogels strongly depend on the and charge characteristics of the nanoemulsions.
Conclusions:
These findings indicate that positive charge nanoemulsion may be a promising vehicle for topical use of CSA to treat ocular immune-mediated diseases.
Keywords: 489 cyclosporine •
607 nanotechnology •
483 cornea: storage