Description

Fk-506-13C-D2 is a stable isotope-labeled analog of the potent immunosuppressant Tacrolimus, specifically labeled with carbon-13 and deuterium. This high-purity reference standard is critical for ensuring accuracy and reliability in quantitative bioanalytical research and method development. It is an essential tool for scientists in pharmaceutical development and clinical research who require precise internal standards for mass spectrometry (LC-MS/MS) to study drug metabolism, pharmacokinetics, and therapeutic drug monitoring. The compound is supplied with full analytical characterization to support rigorous quality control in regulated environments.

Application

• Primary use as an Internal Standard for the quantitative analysis of Tacrolimus (FK506) in biological matrices via LC-MS/MS.
• Critical for Pharmacokinetic (PK) and Bioequivalence Studies, enabling accurate measurement of drug concentration in plasma, blood, or tissue.
• Method development and validation in Clinical Research and therapeutic drug monitoring (TDM) for transplant patients.
• Metabolite identification and Drug Metabolism and Pharmacokinetics (DMPK) studies in preclinical and clinical stages.
• Use in Forensic Toxicology and anti-doping control for the definitive identification and quantification of Tacrolimus.
• Calibration and quality control in Contract Research Organizations (CROs) and analytical testing laboratories.
• Supporting research into immunosuppressive therapies and Biomarker Discovery related to calcineurin inhibition.

Basic Information

Product Name	Fk-506-13C-D2
CAS No.	1356841-89-8
Molecular Formula	C44H6713C D2NO12 • xH2O
Molecular Weight	~ 821.0 g/mol (anhydrous basis)
Synonyms	Tacrolimus-13C,D2; FK-506-13C,D2; (3S,4R,5S,8R,9E,12S,14S,15R,16S,18R,19R,26aS)-5,6,8,11,12,13,14,15,16,17,18,19,24,25,26,26a-Hexadecahydro-5,19-dihydroxy-3-[2-(4-hydroxy-3-methoxycyclohexyl)-1-methylethenyl]-14,16-dimethoxy-4,10,12,18-tetramethyl-8-(2-propenyl)-15,19-epoxy-3H-pyrido[2,1-c][1,4]oxaazacyclotricosine-1,7,20,21(4H,23H)-tetrone-13C,D2; Deuterated and 13C-labeled Tacrolimus; Stable Isotope Labeled Tacrolimus; Immunosuppressant Reference Standard-13C,D2.
EINECS	Contact for details

Quality Control

Our Fk-506-13C-D2 is manufactured under strict quality systems to ensure the highest isotopic and chemical purity for demanding analytical applications. Each batch is accompanied by a comprehensive Certificate of Analysis (COA) detailing results for isotopic enrichment, chemical purity, and identity confirmation. We adhere to relevant industry guidelines for reference standards. Certificates of Analysis (COA) are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store at -20°C or below in a dry environment. This product is hygroscopic (moisture-sensitive). Allow the vial to equilibrate to room temperature in a desiccator before opening to minimize moisture uptake.

Specification

Item	Specification
Appearance	White to off-white solid
Identification (IR)	Conforms to structure
Identification (HPLC)	Retention time corresponds to reference
Purity (HPLC)	≥ 98.0%
Isotopic Enrichment	≥ 99 atom % 13C; ≥ 98 atom % D
Chemical Purity	≥ 95% (by NMR)
Water Content (KF)	≤ 5.0%
Residual Solvents (GC)	Complies with ICH limits

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