Description

Cis,trans-Doxepin-D3 is a deuterium-labeled isotopologue of the tricyclic antidepressant doxepin, specifically designed for use as an internal standard in analytical chemistry. This compound is critical for ensuring the accuracy and reliability of quantitative analyses, particularly in pharmacokinetic and bioequivalence studies. It is an essential tool for pharmaceutical R&D laboratories, contract research organizations (CROs), and regulatory testing facilities that require high-precision mass spectrometry methods.

Application

• Primary use as an internal standard in Liquid Chromatography-Mass Spectrometry (LC-MS/MS) and Gas Chromatography-Mass Spectrometry (GC-MS) for the quantification of doxepin and its metabolites.
• Critical component in bioanalytical method development and validation for clinical and preclinical studies.
• Enables accurate therapeutic drug monitoring (TDM) in patient plasma or serum samples.
• Supports pharmacokinetic (PK) and toxicokinetic (TK) research by providing a stable isotopic reference.
• Used in forensic and anti-doping analysis for the definitive identification and measurement of doxepin.
• Facilitates drug metabolism and disposition (DMPK) studies in pharmaceutical development.
• Essential for ensuring data integrity and compliance in Good Laboratory Practice (GLP) and Good Clinical Practice (GCP) environments.

Basic Information

Product Name	Cis,trans-Doxepin-D3
CAS No.	138387-16-3
Molecular Formula	C19H18D3NO
Molecular Weight	282.40 g/mol
Synonyms	Doxepin-d3; Doxepin (D3); 1-Propanamine, 3-dibenz[b,e]oxepin-11(6H)-ylidene-N,N-dimethyl-, (E)-, D3-labeled; (E)-3-(Dibenz[b,e]oxepin-11(6H)-ylidene)-N,N-dimethyl-1-propanamine-d3; NSC 108160-d3; P-3693A-d3; Sinequan-d3; Adapin-d3; Deuterated Doxepin
EINECS	Contact for details

Quality Control

Our Cis,trans-Doxepin-D3 is manufactured under strict quality systems to ensure the high chemical and isotopic purity required for trace analysis. Each batch is accompanied by a comprehensive Certificate of Analysis (COA) detailing results for identity, purity (by HPLC), isotopic enrichment, and residual solvents. We support GLP-compliant research and can provide stability data and method support documentation upon request.

Storage

Preserve in a tightly closed container, protected from light. Store at controlled room temperature, 15-25°C (59-77°F). The product is light-sensitive and should be stored away from light. Keep the container sealed in a dry, well-ventilated place.

Specification

Item	Specification
Appearance	White to off-white solid
Identification (IR)	Conforms to structure
Identification (MS)	Conforms to structure
Purity (HPLC)	≥98.0% (sum of cis and trans isomers)
Isomeric Ratio (cis/trans)	Typically ~15:85
Isotopic Enrichment	≥98 atom % D
Chemical Purity (Titration)	≥97.0%
Residual Solvents (GC)	Complies with ICH guidelines

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.