Tailored gatifloxacin Pluronic® F-68-loaded contact lens: Addressing the issue of transmittance and swelling

Loading of gatifloxacin in contact lenses affects critical lens properties (optical and swelling) owing to drug precipitation in the contact lens matrix. The presence of Pluronic (R) F-68 in the packaging solution creates in-situ micelles in the contact lens to dissolve gatifloxacin precipitates and provide sustained drug release. The micelles further improved the drug uptake from the drug-packaging solution to create an equilibrium of drug between the lens matrix and the packaging solution. In this study, we optimized gatifloxacin-pluronic-loaded contact lenses to achieve the desired optical transmittance, swelling, and gatifloxacin loading capacity as well as sustained drug delivery. Optimization of gatifloxacin-pluronic-loaded contact lens was carried out using a 3(2) factorial design by tailoring the concentration of Pluronic (R) F-68 in the packaging solution (X-1) and the amount of gatifloxacin in the monomer solution (X-2) to achieve the desired lens properties. The optimized batch (X-1 = 0.3%w/v and X-2 = 0.3%w/v) showed an optical transmittance of 92.84%, swelling of 92.36% and gatifloxacin loading capacity of 92.56 pg. The in vitro flux data of the optimized batch (GT-Pl-CL) showed sustained release up to 72 h, whereas soaked contact lenses (SM-CL) and direct gatifloxacin-loaded contact lenses (DL-CL) showed a sustained release up to 48 h. The in vivo gatifloxacin release data for rabbit tear fluid showed sustained release with a high gatifloxacin level for the GT-Pl-CL lens in comparison to the SM-CL and the eye drop solution. This study demonstrates the application of the 3(2) full factorial design to optimize gatifloxacin-pluronic-loaded contact lenses to achieve the desired optical transmittance, swelling, and drug loading capacity.