Enhancement of the ocular therapeutic effect of prednisolone acetate by liposomal entrapment.

Eye drops account for 90% of ophthalmic formulations despite of the rapid precorneal drug loss. Our aim is to test the effect of positive charge induction and the subsequent size reduction on the efficiency of liposomes as ocular drug delivery system for the lipophilic drug prednisolone acetate (PSA). Different formulations of PSA-loaded liposomes, positive multilamellar liposomes (pMLV), positive small (nano-sized) unilamellar liposomes (pSUV) and neutral multilamellar liposomes (nMLV), were prepared.