Bimatoprost-loaded lipidic nanoformulation development using quality by design: liposomes versus solid lipid nanoparticles in intraocular pressure reduction

Background: Bimatoprost is a drug used to lower intraocular pressure in the treatment of glaucoma. Conventional eye drops have the limitations of repeated dosing, drug loss due to tear outflow and hence poor availability for action. Materials & methods: Using a systematic quality by design approach, liposomes and solid lipid nanoparticles were formulated and further encapsulated in thermo-sensitive in situ hydrogel. Results & conclusion: Optimized liposomes had 87.04% encapsulation efficiency and 306.78 nm mean particle size, while solid lipid nanoparticles had 90.51% and 304.21 nm. Bimatoprost liposomes had controlled zero-order drug kinetics and no initial burst release, making them better than solid lipid nanoparticles. Bimatoprost-loaded liposomes in thermo-sensitive hydrogel decreased intraocular pressure for 18 h.