Greenness assessment of micellar spectrofluorometric approach for determination of Elagolix: application to dosage form, content uniformity and human plasma

Forced degradation studies of elagolix sodium with the implementation of high resolution LC-UV-PDA-MSn (n = 1,2,3…) and NMR structural elucidation

Elagolix sodium (ELS) is a marketed product using to release moderate to severe endometriosis-associated pain. It contains functional groups such as carboxyl group, secondary amino group, 2,4-dioxo pyrimidinyl and several benzyl or benzyl-like position hydrogen atom that are susceptive to occur stress degradation. Forced degradation studies of ELS reveal different degradation profiles of the drug substance which are conducted under photo, thermal, acidic, neutral, alkaline and hydrogen peroxide oxidative conditions in the direction of the ICH guidances. With structural elucidation of LC-PDA/UV-MSⁿ and NMR, the degradants were identified, and seven new degradants are reported in this study. It is confirmed that most of the degradation behaviors of ELS are related to the carboxyl group and secondary amino group in the 3-carboxyl propylamine side chain. Under the oxidative condition using hydrogen peroxide as the oxidant, the secondary amine was oxidized to form an N-hydrogen amine degradant and two further degradants of amine and carbonyl analogs were generated. Under the alkaline degradation condition, the ELS is proven to be stable and no obvious degradants are produced. On the other hand, under the acidic and neutral degradation condition, the 2,4-dioxo pyrimidinyl core of elagolix sodium is stable but the carboxyl group and secondary amine will occur ring cyclization to form the δ-lactam analogs of elagolix sodium. The plausible mechanisms for the degradation of acidic, thermal, photo-degradative and hydrogen peroxide mediated oxidative of elagolix sodium are proposed. It is worth to note that DP-3-4 are the potential degradants which are only found in the solution degradation and are not the real impurities of elagolix sodium.

Ultra-sensitive and selective fluorescence approach for estimation of elagolix in real human plasma and content uniformity using boron-doped carbon quantum dots

Elagolix (ELX) is an orally administered non-peptidic GnRH antagonist that has been approved by the Food and Drug Administration in 2018 for the treatment of endometriosis pain. A sensitive and selective method for estimating elagolix (ELX) in human plasma and content uniformity was developed and validated. The spectrofluorimetric technique was used to investigate ELX utilizing boron-doped carbon quantum dots (B@CQDs). After gradually adding ELX, the quantum dots fluorescence was enhanced with LOQ of 1.74 ng mL⁻¹, the calibration curve between ELX and corresponding fluorescence intensity was found over a range of 4–100 ng mL⁻¹. The method was successfully applied in real human plasma with pharmacokinetic study and content uniformity test. The pharmacokinetic parameters as C_max were found to be 570 ± 5.32 ng. mL⁻¹ after 1 h, t_1/2 was found to be 6.50 h, and AUC was found to be 1290 ± 30.33 ng. h. mL⁻¹. B@CQDs were characterized using variety of instruments. The strategy is simple to implement in clinical labs and therapeutic drug monitoring systems.