[CAS Number 347840-07-7] Doxepin-D3.HCl is an internal standard used for the quantification of doxepin.HCl. Doxepin.HCl is a tricyclic antidepressant possessing antipruritic and sedative qualities. Sold under brand names such as Silenor and Aponal, Doxepin.HCl is used to treat sleeping problems and anxiety disorders, and chronic hives to a lesser extent. Doxepin-D3.HCl is available as reference material (bulk powder and/or solution) and as calibrated, Ready-to-Use, certified reference material (CRM). This product is designed for qualitative and quantitative protocols and can be used for forensic, toxicology, research, and other chemical/biochemical analytical applications.