Fig. 4
From: Revisiting atenolol as a low passive permeability marker
The ratio of unbound S-atenolol in rat brain ECF to that in plasma (Cu,brain/Cu,plasma) versus time for Group 1 (solid circles and lines) with 15-min fast i.v. infusion followed by 165-min slow i.v. infusion (n = 9) and for Group 2 (open circles and dashed lines) with 180-min constant i.v. infusion. The unbound partition coefficient (Kp,uu,brain) was calculated during steady state (between 90 and 180 min) for Group 1