Exploring the Role of Sodium Dodecyl Sulfate Surfactant in Enhancing the Fluorescence Properties of Besifloxacin Fluoroquinolone; Application to Eye Formulations and Artificial Aqueous Humor

An ultrasensitive, selective, rapid, and cost-effective spectrofluorimetric approach is established and validated to quantify the ophthalmic fluoroquinolone antibiotic, besifloxacin (BN), in its ophthalmic preparations and artificial aqueous humor. Unlike previously reported methods that require costly fluorogenic derivatization reagents, lengthy analytical procedures, or expensive instrumentation, the proposed approach offers a simple and highly sensitive alternative method for detecting BN. The suggested method relies on using 2.0% w/v sodium dodecyl sulfate (SDS) as a micellar system in an acetate buffer solution (pH 3.6) to boost the fluorescence intensity of BN at λ_em of 446 nm. The fluorescence intensity of BN was remarkably amplified by around 2.6 folds compared to the BN in acetate buffer without SDS surfactant. The linearity range of the developed method was 5.0-100 ng/mL with detection and quantitation limits of 0.64 and 1.93 ng/mL, respectively. Moreover, the proposed micellar system has been effectively used for the assay of the BN in eye drops and artificial aqueous humor and the achieved percentage recoveries for artificial aqueous humor samples were in the range of 98.82 ± 1.89-103.08 ± 1.60%.