Pactimibe sulfate is a selective inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT), primarily researched for its potential in managing lipid disorders and preventing atherosclerosis. By inhibiting ACAT, it reduces the esterification of cholesterol in cells, particularly in macrophages within arterial walls, thereby limiting foam cell formation and plaque development. This mechanism positions it as a candidate for treating hypercholesterolemia and cardiovascular diseases, including reducing risks of heart attacks and strokes. It is especially relevant for patients unresponsive to statins or needing adjunct therapies. Although phase III trials did not demonstrate sufficient efficacy for approval, it remains valuable in ongoing preclinical and research studies to assess its safety, pharmacokinetics, and potential applications in lipid management.