PDE2/PDE10-IN-1

The PK properties of PDE2/PDE10-IN-1 are studied in rats after 2.5 mg/kg i.v. and 10 mg/kg p.o. administration. After i.v. administration, a rapid clearance is observed (t_1/2=0.47 h), which is not expected based on the in vitro metabolic stability in rat liver microsomes (rLMs). Interestingly, PDE2/PDE10-IN-1 shows much slower clearance after p.o. administration (t_1/2=2.36 h), resulting in good bioavailability and a maximum plasma concentration (C_max) of 997 ng/mL. PDE2/PDE10-IN-1 is assessed for its potential to cross the blood–brain barrier in rats after 10 mg/kg s.c. administration. PDE2/PDE10-IN-1 shows good formulatability with 10 to 20% HPβCD at pH>3.5. The brain concentration for PDE2/PDE10-IN-1 after 1 h administration is in the range of 370-895 ng/g with high brain free fractions and brain/plasma ratios. More specifically, PDE2/PDE10-IN-1, which is orally bioavailable, occupies PDE2 with an ED₅₀ of 21 mg/kg^[1].