Pactimibe (CS-505 free base) is a dual ACAT1/2 inhibitor with IC 50 s of 4.9 μM and 3.0 μM, respectively. Pactimibe (CS-505 free base) inhibits ACAT with IC 50 s of 2.0 μM, 2.7 μM, 4.7 μM in the liver, macrophages and THP-1 cells, respectively Pactimibe (CS-505 free base) noncompetitively inhibits oleoyl-CoA with a K i value of 5.6 μM. Moreover, Pactimibe (CS-505 free base) obviously inhibits cholesteryl ester formation with an IC 50 of 6.7 μM. Pactimibe (CS-505 free base) possesses anti-atherosclerotic potential with lowering plasma cholesterol activity . In Vitro Pactimibe (CS-505 free base) induces moderate ACAT inhibition in monocyte-derived macrophages, leading to the suppression of foam cell formation. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Pactimibe (CS-505 free base; 60 and 200 mg/kg/day; oral gavage; twice a day; 12 weeks) induces an inhibition for ACAT-1 and ACAT-2, causing a reduction of plasma cholesterol but no influence on macrophage- or collagen-positive areas. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Male C57BL/6J ApoE −/− mice aged 8-week-oldDosage: 60 and 200 mg/kg/day Administration: Oral gavage; twice a day; 12 weeks Result: Decreased plasma cholesterol levels by 39% and 74% at the administration of 60 and 200 mg/kg/day Form:Solid IC50& Target:ACAT1|4.9 μM (IC|50|)|ACAT2|3.0 μM (IC|50|)|ACAT|2 μM (IC|50|, in the liver)|ACAT|2.7 μM (IC|50|, in macrophages)|ACAT|4.7 μM (IC|50|, in THP-1 cells)|oleoyl-CoA|5.6 μM (Ki)|cholesteryl ester formation|6.7 μM (IC|50|)