Brimonidine base-loaded Solid Lipid Nanoparticles for Ocular Delivery

Using glyceryl monostearate or Precirol® ATO 5 as solid lipid in 4% w/w concentration in addition to 0.05% w/w Poloxamer® 188, as an emulsifier were optimum for entrapping the hydrophobic Brimonidine base. The prepared solid lipid nanoparticles formulations showed uniform, nanosized particles below 500 nm, suitable for ophthalmic application, of good entrapment efficiency and accompanied by a sustained Brimonidine base release, compared to both Brimonidine¿ eye drops and Brimonidine dispersion. Glyceryl monostearate solid lipid nanoparticles formulation showed good corneal permeation and localization of the solid lipid nanoparticles in the anterior ocular chamber, acting as a depot for sustained Brimonidine base release. A significant (P ¿ 0.05) lowering in intraocular pressure compared to Brimonidine¿ eye drops and excellent ocular tolerance were determined. It was concluded that; solid lipid nanoparticles formulation is a promising approach for ocular delivery of Brimonidine base to improve its clinical effect.