Comprehensive review of analytical techniques for evaluating fixed-dose combinations containing timolol

Fixed-dose combinations (FDCs) of timolol with various therapeutic agents for treatment of glaucoma have been found to be more effective than monotherapy or concurrent administration of these agents. In this article the current analytical methods for quantitative determination of timolol in combination with other therapeutic agents intended for treatment of glaucoma in ophthalmic preparation are reviewed. Highpressure liquid chromatography (HPLC) was found to be the most commonly used method followed by UV/Visible spectrophotometry and thin-layer chromatography (TLC). Recent preferences in the analysis of timolol with the anti-glaucoma agents in combination samples prove primacy of HPLC (62.5%) and confirm general trends moving towards more sensitive methods, with higher resolution potential, consuming small quantities of samples and reagents and requires less analysis time. • This review compiles methods for simultaneous determination of timolol with other antiglaucoma agents in bulk and dosage forms. • It covers various fixed-dose combos like timolol/dorzolamide, timolol/brimonidine, and timolol/latanoprost. • Methods include UV, RP-HPLC, HPTLC, and CE, focusing on sensitivity, specificity, and use in routine quality control. • Each method includes operational details, validation (linearity, LOD), and suitability for specific formulations. • The paper organizes data by molecules and analytical techniques, presenting them in tabular form.