Description

Ethosuximide D5 is a deuterated analog of the established anticonvulsant ethosuximide, specifically designed for use as an internal standard in analytical chemistry. This high-purity, isotopically labeled compound is essential for ensuring the accuracy and reliability of quantitative analyses, particularly in pharmacokinetic and metabolic studies. It is a critical material for pharmaceutical R&D laboratories, contract research organizations (CROs), and analytical service providers requiring precise and reproducible results.

Application

• Internal Standard for LC-MS/MS: Primary application as a stable, non-interfering internal standard for the quantification of ethosuximide in biological matrices (plasma, serum, urine) using liquid chromatography-tandem mass spectrometry.
• Pharmacokinetic and Bioavailability Studies: Enables accurate measurement of drug concentration over time, critical for determining absorption, distribution, metabolism, and excretion (ADME) profiles.
• Therapeutic Drug Monitoring (TDM): Supports the development and validation of robust clinical assays to monitor ethosuximide levels in patient samples for dose optimization.
• Metabolite Identification and Profiling: Aids in distinguishing drug-derived metabolites from endogenous compounds in complex biological samples.
• Method Development and Validation: Serves as a key component in establishing and validating new analytical methods according to ICH, FDA, or other regulatory guidelines.
• Quality Control in Pharmaceutical Manufacturing: Can be used in impurity profiling and stability-indicating assays for ethosuximide active pharmaceutical ingredient (API) and finished dosage forms.

Basic Information

Product Name	Ethosuximide D5
CAS No.	1989660-59-4
Molecular Formula	C7H6D5NO2
Molecular Weight	146.19 g/mol
Synonyms	2-Ethyl-2-methylsuccinimide-3,3,4,4,5-d5; (RS)-3-Ethyl-3-methylpyrrolidine-2,5-dione-d5; Ethosuximide-d5; Deuterated Ethosuximide; Ethosuximide (ethyl-d5); Ethosuximide Internal Standard; 3-Methyl-3-ethyl-2,5-pyrrolidinedione-d5; Zarontin-d5 (labeled analog)
EINECS	Contact for details

Quality Control

Every batch of Ethosuximide D5 is produced and analyzed under strict quality management systems. We guarantee high chemical and isotopic purity to meet the exacting demands of analytical applications. Comprehensive testing includes assay by HPLC, determination of isotopic enrichment by NMR or MS, and control of related substances. A detailed Certificate of Analysis (COA) is provided with each shipment, documenting all critical quality attributes.

Storage

Preserve in a tightly closed container, protected from light. Store at controlled room temperature (15-25°C) in a dry environment. For long-term storage, consider keeping the material under inert atmosphere to ensure stability.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Identification (MS)	Conforms to structure
Purity (HPLC)	≥ 98.0%
Isotopic Purity (D-content)	≥ 98.0 atom % D
Chemical Purity (NMR)	Conforms
Residual Solvents (GC)	Complies with ICH Q3C
Water Content (KF)	≤ 0.5%

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