“…To enhance the ocular retention of ophthalmic drugs, various strategies including viscous polymer solutions, adhesive microparticles [ 5 , [9] , [10] , [11] , [12] , [13] ], and hydrogels [ [14] , [15] , [16] ] have been proposed. Among them, hydrogels attracted the most attentions as increasing retention time on ocular surface, high moisturizing, and good compatibility [ [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] ], and the retention time can be extended by almost three times when the formulation was changed from solution to hydrogel [ 14 , 22 ]. Traditional ophthalmic gel is prepared by encapsulation of antibiotic drugs via viscous polymer matrix such as Carbomer [ 26 ], or thermo-sensitive polymers such as Pluronic F127 [ 27 ].…”