Formulation development and in vitro evaluation of transferrin-conjugated liposomes as a carrier of ganciclovir targeting the retina.

Ganciclovir (GCV) is an antiviral drug approved for treatment of cytomegalovirus (CMV) retinitis. It can be delivered to the eye via systemic administrations. However, local delivery of GCV that targets the retina is considered as an alternative to increase efficacy of the treatment and lessen side effects. Thus, this study aimed to develop formulations of transferrin (Tf)-conjugated liposomes containing GCV (Tf-GCV-LPs) for intravitreal injection and topical instillation. Tf-GCV-LPs were prepared by the reverse-phase evaporation technique and then conjugated to Tf. Their physicochemical properties were evaluated. The optimized formulation was selected and subjected to the cytotoxicity test, cellular uptake study in the human retinal pigment epithelial cells (the ARPE-19 cells) and antiviral activity evaluation. The results showed that physicochemical properties of Tf-GCV-LPs were affected by formulation compositions. The optimized Tf-GCV-LPs had a particle size lower than 100 nm with a negative value of zeta potential. They were safe for the ARPE-19 cells. These Tf-GCV-LPs were taken up by these cells via Tf receptors-mediated endocytosis and showed inhibitory activity on CMV in the infected cells. Therefore, the optimized Tf-GCV-LPs could be accepted as a promising drug delivery system for targeted GCV delivery to the retina in the treatment of CMV retinitis.