RETRACTED: Controlled brimonidine release from nanostructured lipid carriers-laden silicone contact lens to treat glaucoma

Abstract

A novel brimonidine-loaded nanostructured lipid carriers (Br-NLCs)-laden silicone contact lenses were designed for control ocular delivery of brimonidine for effective treatment of glaucoma. The Br-NLCs were found to be spherical in shape with an average size of 100–140 nm and a zeta potential of −31.1–33.7 mV. Compared to conventional soaked contact lenses (Br-SM), Br-NLCs-laden contact lenses improved critical lens properties such as swelling, optical transmittance, and protein adherence. Furthermore, Br-SM contact lens showed low brimonidine uptake, high burst release, and short release duration up to 24 h compared to Br-NLCs-laden contact lens that showed high brimonidine uptake, and the cumulative release was sustained up to 144 h. The ability to sustain the release of brimonidine improved proportionally with an increase in the amount of liquid lipid (oleic acid) in the NLCs. The Br-NLCs-laden contact lens was found to be safe in ocular irritation and histopathological studies. In the rabbit tear fluid model, Br-NLC-30%-OA-CL batch showed high brimonidine concentration at all-time points up to 144 h. Further, pharmacodynamic study showed sustained reduction in IOP by Br-NLC-30%-OA-CL batch for 144 h compared to 72 h and 6 h with Br-SM lens and eye drop solution, respectively. In conclusion, Br-NLCs enhanced brimonidine uptake in the contact lens from the soaking solution and showed control brimonidine release to manage glaucoma with better clinical outcomes to substitute eye drop therapy.