N desmethyl tamoxifen hydrochloride

Antipyrine, cimetidine, clotrimazole, N-desmethyl-tamoxifen hydrochloride, furosemide, hydrochlorothiazide, ketoprofen, maleic acid, (+/−)-metoprolol-(+)-tartrate, (+/−)-norverapamil hydrochloride, piroxicam, tamoxifen, terbutaline hemisulfate and (+/−)-verapamil hydrochloride 99% were purchased from Sigma-Aldrich (St. Louis, MO, USA); (+/−)-propranolol hydrochloride and ranitidine hydrochloride were obtained from Alfa Aesar GmbH & Co KG (Karlsruhe, Germany), and carbamazepine was purchased from Acros Organics (New Jersey, USA). Midazolam and α-hydroxyMidazolam were purchased from Lipomed AG (Arlesheim, Switzerland), and agar, calcium chloride dihydrate, glucose hydrate, magnesium chloride hexahydrate, potassium chloride, sodium chloride, sodium hydroxide, sodium phosphate monobasic and sodium hydrogencarbonate were obtained from Hänseler AG (Herisau, Switzerland). Sodium taurocholate was purchased from Prodotti Chimici e Alimentari S.p.A., (Basaluzzo, Italy) and lecithin (grade EPCS > 98% phospholipids) was obtained from Lipoid GmbH (Ludwigshafen, Germany).

Tamoxifen citrate salt (>98%) was obtained from TCI chemicals (TCI, Portland, Oregon, USA). 4-hydroxytamoxifen (>98%), N-desmethyltamoxifen hydrochloride (>98%), E/Z endoxifen hydrochloride (>98%) and heparin were obtained from Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). 5-methylflavone (internal standard) was purchased from Tokyo Chemical Industry. LC-MS grade organic solvents, including methanol, acetonitrile, formic acid, and ammonium bicarbonate, were acquired from Merck Co. (Darmstadt, Germany). Purified deionized water was produced using a Milli-Q system (Millipore, Milford, MA, USA).