Formulation and evaluation of ocular self-nanoemulsifying drug delivery system of brimonidine tartrate

The aim of the current study was to develop an ocular Self-nanoemulsifying drug delivery system (SNEDDS) loaded with Brimonidine tartrate (BRT) and evaluate its ex-vivo permeability. SNEDDS loaded with BRT were prepared by low energy method. Physicochemical properties, drug release, ex-vivo permeation, and toxicity studies were investigated. The BRT-loaded SNEDDS formulation was composed of Capmul MCM (Oil), Tween 80 (Surfactant), and Transcutol HP (Co-surfactant) and was optimized by Box-Behnken design. Optimized SNEDDS loaded with BRT had a droplet size of 118.3 nm, a PDI of 0.251, a pH of 6.34 +/- 0.31, an osmolarity of 329 mosm/ L after reconstitution with NaCl, and a viscosity was found to be 12.39 +/- 2.31 cP. The optimized SNEDDS loaded with BRT had excellent stability in the shelving period. The apparent permeability coefficient of optimized SNEDDS was found to be (7.078 +/- 0.218 x 10-6 cm/s) when compared to the marketed formulation with (3.127 +/- 0.173 x 10-6 cm/s). These results suggest that Brimonidine tartrate-loaded SNEDDS can be used as a promising nanocarrier for ocular drug delivery.