Identification and characterization of trametinib degradation product employing Orbitrap LC-HRMS, and development of a robust, eco-friendly stability indicating method of analysis

Abstract

Trametinib is a selective MEK1/2 inhibitor approved for the treatment of various cancers. Stress testing of a drug is essential for understanding the stability profile and ensuring compliance with regulatory requirements during pharmaceutical development. To the best of our knowledge, only a few reports on stress testing of trametinib are available to date. Moreover, comprehensive reports on the stress testing of trametinib using LC-HRMS are not available in any literature. Therefore, the present study aimed to conduct stress studies on trametinib in accordance with ICH guidelines. The RP-HPLC stability-indicating analytical method was developed, and the stress degradation condition for trametinib was optimised. Chromatographic separation of trametinib and its degradation products was achieved on a Phenomenex Luna C18 column (250 × 4.6 mm, 5 µm) using a mobile phase consisting of 0.1 % formic acid in Milli-Q water and acetonitrile using gradient elution. The proposed method demonstrated excellent specificity, linearity, precision (RSD ≤ 0.09 %), and accuracy (99.78–101.38 %). Results indicate that trametinib exhibited high susceptibility to acidic and basic stress conditions, whereas it remained relatively stable under oxidative and thermal stress conditions. All degradation products were characterised using Orbitarp LC-HRMS in positive HESI mode (m/z 50–800 Da) for accurate mass determination and fragmentation pathway elucidation. In-silico toxicity prediction suggested that among the degradation products, neurotoxicity was the most consistently predicted endpoint with high confidence (≥70 %), followed by respiratory toxicity and immunotoxicity. Greenness evaluation using AGREE, Eco-Scale, and BAGI tools indicated a moderate environmental impact.