Telotristat (LP-778902) is a potent tryptophan hydroxylase inhibitor with an in vivo IC 50 of 0.028 μM. In Vitro Telotristat is the active moiety of telotristat etiprate. Telotristat etiprate is an ethyl ester prodrug which is hydrolyzed to telotristat. Telotristat etiprate is orally available serotonin synthesis inhibitor for the treatment of carcinoid syndrome. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Telotristat etiprate is present in very low levels after oral administration. These low levels are due to rapid hydrolysis into the active moiety telotristat. The half-life ranges from approximately 4-12 h. There is no accumulation of telotristat with multiple dose administration over 2 weeks. Exposure to telotristat is approximately dose proportional . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Cell Assay BON CBA cells are grown in equal volume of DMEM and F12K with 5% bovine serum for 3-4 hours (20 K cell/well) and telotristat is added at a concentration range of 0.07 to 50 μM. The cells are incubated at 37°C overnight. 50 μM of the culture supernatant is then taken for 5HTP measurement. The supernatant is mixed with equal volume of 1M TCA, then filtered through glass fiber. The filtrate is loaded on reverse phase HPLC for 5HTP concentration measurement. The cell viability is measured by treating the remaining cells with Celltiter-Glo Luminescent Cell Viability Assay. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal administration Rats: 14-week-old male C57 albino mice are dosed once daily by oral gavage at 5-10 mL/kg for four consecutive days. Five hours after the last dose, the animals are quickly sacrificed. 5-HT is extracted from the blood or tissues and measured by HPLC. Blood samples are taken for exposure analysis . aladdin has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:IC50: 0.028 μM (tryptophan hydroxylase)