Determination of Flibanserin in Female Sexual Desire Enhancer Products by LC–MS/MS and Its Confirmation by LCMS-IT-TOF

Hypoactive sexual desire disorder, a common condition among females, often goes undiagnosed due to the lack of available pharmaceutical treatments or the stigma associated with this condition. Flibanserin was initially investigated as an antidepressant but failed to demonstrate efficacy for depression; however, subsequent clinical studies revealed its potential to enhance sexual desire in some individuals, leading to its approval by the U.S. Food and Drug Administration in 2015 for the treatment of hypoactive sexual desire disorder. In this study, a novel LC-MS/MS method was developed and validated for the determination of flibanserin in commercial products marketed in Türkiye as female sexual desire enhancers. Chromatographic separation was achieved using a SunShell C18 column (100 mm × 4.6 mm, 2.6 μm), with a mobile phase consisting of 0.1% formic acid in methanol and 0.1% formic acid in water (65:35, <i>v</i>/<i>v</i>). The method exhibited a low limit of quantification (1.00 ng/mL) and a short analysis time of 5 min. The method was fully validated in accordance with the ICH Q2-(R2) guideline. Accuracy studies performed on samples in which flibanserin was not detected yielded recovery values between 90.04% and 94.60%. Interday linearity studies conducted over 3 days showed no statistically significant differences (<i>p</i> = 0.9823, ANOVA). Commercial samples collected from various sources were analyzed using both LC-MS/MS and LC-MS-IT-TOF techniques, revealing the absence or very low levels of flibanserin in the investigated products, raising concerns regarding product authenticity and potential risks to women's health. In addition, the proposed analytical approach was evaluated using greenness, blueness, and whiteness metrics, demonstrating its suitability as a sustainable and applicable method for routine control analyses.