“…Dipivefrin showed enhanced corneal penetration with I0 times improved therapeutic index compared to epinephrine [17, 18]. Since then, a plethora of ester prodrugs including adrenergic agonists [19, 20], adrenergic antagonists [21, 22], cholinergics [23, 24], carbonic anhydrase inhibitors [25], prostaglandins [5, 26], antimetabolites [6, 27] and steroids [28, 29] have been prepared and their pharmacokinetic behaviors have been thoroughly explored Ester prodrugs can enhance corneal penetration with improved therapeutic index. However, in some instances these components appear to be chemically instable in aqueous eye drop formulations.…”