As with other topically administered ophthalmic drugs, VEXOL® 1% (rimexolone ophthalmic suspension) is absorbed systemically. Studies in normal volunteers dosed bilaterally once every hour during waking hours for one week have demonstrated serum concentrations ranging from less than 80 pg/mL to 470 pg/mL. The mean serum concentrations were approximately 130 pg/mL. Serum concentrations were at or near steady state after 5 to 7 hourly doses. After decreasing the dosing frequency to once every two hours while awake during the second week of administration, mean serum concentrations were approximately 100 pg/mL.