Tetraisopropyl 2-(3,5-Di-Tert-Butyl-4-Hydroxyphenyl)Ethyl-1,1-Biphosphonate (also known as SR-9223I and SR 45023A) is a gem-diphosphonate derivative patented by Symphar S. A. as an antihypertensive and anti-inflammatory agent. Tetraisopropyl 2-(3,5-Di-Tert-Butyl-4-Hydroxyphenyl)Ethyl-1,1-Biphosphonate acts as 3-hydroxy-3-methylglutaryl reductase inhibitor, besides that SR-9223I suppresses acyl-CoA: cholesterol acyltransferase activity and prevents the oxidation of plasma lipoproteins. In preclinical studies, SR-9223i reduces blood cholesterol concentrations in mice, hamsters, dogs, and monkeys. SR-9223i inhibits the growth of a wide variety of tumor cell lines in vitro and triggered apoptosis in HL60 cells in less than 2 h. SR-9223i induces caspase-3 activity at concentrations similar to it’s IC(50) values for cell proliferation. Unfortunately, in clinical trials SR-9223I failed to demonstrate efficacy in patients with refractory melanoma and further development was discontinued.