Design of Tranilast-Loaded Cation-Type Contact Lens for Sustainable Ocular Drug Delivery

Objectives: This study evaluated the design of a sustained-release contact lens (CL) device loading tranilast (TRA) and determined the usefulness of these CLs in Japanese albino rabbits. Methods: The sustainable CLs in this study were prepared by combining three CLs with different water contents and soaking methods under high-pressure and high-temperature using an autoclave method (AC-method). Results: Both the CLs prepared with the conventional soaking method (stir-method) and AC-methods were transparent in all three types of CLs. The loaded TRA contents in the CLs when using the AC-method were higher than those prepared using the stir-method for all three types of CLs. TRA contents were also higher when loaded into the cation-type lenses as compared to the other lenses. Moreover, the sustainable release of TRA from the TRA-loaded cation-type CL using the AC-method was significantly higher than those found for the other CLs. No corneal wounds were observed in any of the rabbits given the three types of TRA-loaded CLs for 7 days. Furthermore, the TRA-loaded CL sustainably released TRA into the lacrimal fluid in the rabbit. Conclusions: The TRA-loaded CL prepared using the AC-method overcame the limitations normally associated with the stir-method, such as the high burst release and low drug uptake.