Description

Epalrestat Impurity 4 is a designated chemical reference standard used in the analytical profiling and quality control of the active pharmaceutical ingredient (API) Epalrestat. This compound is critical for ensuring the purity, safety, and efficacy of Epalrestat, a medication used to treat diabetic neuropathy. It is an essential tool for pharmaceutical manufacturers, analytical laboratories, and regulatory bodies involved in research, development, and compliance testing.

Application

• Pharmaceutical Reference Standard: Primary use as a certified impurity standard for the identification and quantification of Epalrestat Impurity 4 in Epalrestat API and finished drug products.
• Analytical Method Development & Validation: Crucial for developing, optimizing, and validating HPLC, UPLC, or LC-MS methods to monitor impurities.
• Quality Control & Assurance (QC/QA): Used in routine batch release testing to ensure API and drug formulations meet stringent pharmacopeial (e.g., USP, EP) and ICH Q3A/B guidelines for impurity limits.
• Stability Studies: Employed to track the formation and level of this specific impurity during forced degradation and long-term stability studies of Epalrestat.
• Regulatory Submissions: Provides essential data for regulatory filings (e.g., ANDA, NDA, CMC sections) to demonstrate comprehensive impurity control strategies.
• Research & Development: Supports synthetic route optimization and process chemistry by identifying and characterizing process-related impurities.

Basic Information

Product Name	Epalrestat Impurity 4
CAS No.	130786-32-2
Molecular Formula	Contact for details
Molecular Weight	Contact for details
Synonyms	Epalrestat Related Compound 4; Epalrestat Impurity D; 5-[(2Z)-2-Methyl-3-phenyl-2-propen-1-ylidene]-4-oxo-2-thioxo-3-thiazolidineacetic Acid (related); Aldose Reductase Inhibitor Impurity; (Z)-5-(3-Phenyl-2-methylallylidene)-4-oxo-2-sulfanylidene-1,3-thiazolidine-3-acetic Acid (impurity form); Epalrestat Process Impurity; Epalrestat Specified Impurity
EINECS	Contact for details

Quality Control

Every batch of Epalrestat Impurity 4 is manufactured and handled under strict quality management systems. The product undergoes rigorous identity confirmation, purity analysis, and impurity profiling using advanced techniques such as HPLC, LC-MS, and NMR to ensure it meets the high standards required for use as a pharmaceutical reference material. A comprehensive Certificate of Analysis (COA) is supplied with each lot, detailing batch-specific results and confirming compliance with in-house specifications aligned with ICH guidelines.

Storage

Preserve in a tightly closed container, protected from light. Store at controlled room temperature, typically between 15-25°C, in a dry environment. For long-term stability, consider storage under inert atmosphere if specified.

Specification

Item	Specification
Appearance	White to off-white solid
Identification (HPLC)	Retention time matches reference standard
Identification (IR)	Spectrum conforms to reference spectrum
Purity (HPLC)	≥ 95.0%
Related Substances (HPLC)	Total impurities ≤ 5.0% Any individual unspecified impurity ≤ 1.0%
Residual Solvents (GC)	Complies with ICH Q3C guidelines

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