Description

Levothyroxine Impurity 16 is a high-purity reference standard used for analytical and research purposes. This compound is critical for ensuring the quality, safety, and efficacy of levothyroxine sodium, a widely prescribed thyroid hormone replacement therapy. It is primarily required by pharmaceutical manufacturers, analytical laboratories, and regulatory bodies for method development, validation, and quality control testing. The availability of this well-characterized impurity standard is essential for compliance with stringent pharmacopeial guidelines.

Application

• Primary use as a certified reference standard for the identification and quantification of impurities in levothyroxine sodium active pharmaceutical ingredient (API) and finished dosage forms.
• Critical component in analytical method development and validation (HPLC, UPLC, LC-MS) for stability-indicating assays.
• Essential for conducting pharmaceutical stability studies to monitor degradation profiles and establish shelf-life.
• Used in regulatory compliance and quality assurance programs to meet ICH, USP, and EP requirements for impurity profiling.
• Valuable tool for research and development into the synthesis, metabolism, and degradation pathways of thyroxine analogs.
• Supports pharmacopoeial testing and the creation of in-house secondary reference standards.

Basic Information

Product Name	Levothyroxine Impurity 16
CAS No.	909279-46-5
Molecular Formula	Contact for details
Molecular Weight	Contact for details
Synonyms	L-Thyroxine Impurity 16; Thyroxine Related Compound 16; 3,5-Diiodo-L-thyronine Impurity; O-(4-Hydroxy-3,5-diiodophenyl)-3,5-diiodo-L-tyrosine Impurity; Levothyroxine Sodium Impurity 16; T4 Impurity 16; (2S)-2-Amino-3-[4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]propanoic acid (related impurity)
EINECS	Contact for details

Quality Control

Every batch of Levothyroxine Impurity 16 is manufactured and handled under strict quality management systems. The material undergoes comprehensive analytical characterization using advanced techniques including HPLC, LC-MS, and NMR to confirm identity and purity. Our products undergo rigorous quality testing to ensure compliance with industry standards. Certificates of Analysis (COA) with detailed chromatographic data, including batch-specific results for purity and related substances, are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at a controlled room temperature (15-25°C). This material is hygroscopic (moisture-sensitive) and must be kept under anhydrous conditions. For long-term storage, consider storing under an inert atmosphere in a desiccator to maintain stability and purity.

Specification

Item	Specification
Appearance	White to off-white solid
Identification (HPLC)	Retention time corresponds to reference standard
Identification (MS)	Mass spectrum conforms to structure
Purity (HPLC)	≥ 95.0%
Related Substances (HPLC)	Total impurities ≤ 5.0%
Single Unknown Impurity	≤ 1.0%
Water Content (KF)	≤ 1.0%
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.