Integrated Assessment of Three NDSRIs Through CPCA Prioritization, In Silico Toxicity Assessment, and Stability...

Area of Science:

• Pharmaceutical Chemistry
• Analytical Chemistry
• Drug Safety

Background:

• Avatrombopag maleate (AOG), a thrombopoietin receptor agonist, has identified nitrosamine drug substance-related impurities (NDSRIs).
• Assessing and controlling NDSRIs is crucial for generic drug safety and regulatory compliance.

Purpose of the Study:

• To identify and characterize NDSRIs in Avatrombopag maleate (AOG) drug substance.
• To conduct in silico toxicity assessments and establish specification limits using the Carcinogenic Potency Categorization Approach (CPCA).
• To develop and validate a selective, sensitive, and stability-indicating LC-MS/MS analytical method for NDSRI quantification.

Main Methods:

• In silico toxicity assessment and CPCA for NDSRI risk evaluation.
• Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method.
• Forced degradation studies (acid, base, oxidative, thermal, photolytic) to determine NDSRI stability and origin.
• Method validation including specificity, linearity, LOD, LOQ, recovery, precision, and robustness.

Main Results:

• Three new potential NDSRIs were identified in AOG drug substance.
• Specification limits were set at 6.6 ppm based on CPCA (Category 3, AI 400 ng/day).
• The developed LC-MS/MS method demonstrated excellent sensitivity (LOD 0.34 ppm, LOQ 0.67 ppm), linearity (r² > 0.99), and precision (RSD < 2.4%).
• Forced degradation studies confirmed NDSRIs originate from starting materials, not degradation.

Conclusions:

• The identified NDSRIs in AOG are process-related and not degradation products.
• The validated LC-MS/MS method effectively quantifies NDSRIs at trace levels.
• This comprehensive approach ensures AOG product quality and patient safety by meeting regulatory requirements.