# UHPLC-MS-Based Analysis of Fluvoxamine in Rabbit Aqueous Humour and Serum: Method Development and Validation

## TL;DR

This paper develops a reliable method to measure fluvoxamine levels in rabbit eye fluid and blood, supporting its potential use in treating glaucoma with fewer side effects.

## Contribution

A validated UHPLC-MS method for fluvoxamine quantification in aqueous humour and serum is developed and validated for preclinical studies.

## Key findings

- The UHPLC-MS method is linear in the 0.0625–1.5 µg/mL range.
- The method meets EMA guidelines and offers high selectivity and sensitivity.
- It enables accurate pharmacokinetic and pharmacodynamic studies for ocular applications.

## Abstract

Background/Objectives: Fluvoxamine (FLU) is a selective serotonin reuptake inhibitor and one of the most potent agonists of the sigma-1 receptor. Emerging evidence shows that FLU exerts protective effects in multiple organs, making it a promising candidate for topical ocular therapy. Developing an FLU eyedrop for glaucoma can address a significant treatment gap with potentially fewer side effects compared with conventional therapies. To optimise formulation development, precise quantification of FLU in ocular compartments such as aqueous humour, as well as systemic circulation, is essential to characterise drug absorption, ocular bioavailability, and safety. Methods: We developed and validated a UHPLC-MS method for FLU detection in aqueous humour and serum using simple sample preparation steps. Results: The 11-min-long reverse phase chromatography followed by SRM-based mass spectrometry detection provides a highly selective and sensitive FLU detection method. Our method was proved to be linear in the 0.0625–1.5 µg/mL range and was validated according to the EMA guidelines. Conclusions: The simplicity of sample preparation, the tolerable matrix effects, and the favourable detection parameters provide a robust tool for preclinical pharmacokinetic and pharmacodynamic studies of FLU’s ocular protective effects.