Topical ophthalmic antibiotics have low efficacy due to the eye's defense mechanisms. This study incorporated besifloxacin into liposomes with amines as positively charged additives, evaluating the influence of this charge on drug delivery with iontophoretic and passive treatments. Liposomes with phosphatidylcholine (LP PC) or phosphatidylcholine and spermine (LP PC:SPM) were stable, mucoadhesive, and non-irritant. While iontophoresis enhanced permeability for both formulations, the positive charge didn't provide additional iontophoretic advantage. However, LP PC:SPM showed higher passive permeation than Besivance (control) in a novel in vitro model simulating lacrimal flow. Positively charged liposomes improved passive topical delivery, offering a strategy for enhancing topical ophthalmic treatments.

Giselly Almeida dos Santos, Ricardo Ferreira-Nunes, Luciana Facco Dalmolin, Ana Carolina dos Santos Ré, Jorge Luiz Vieira Anjos, Sebastião Antônio Mendanha, Carolina Patrícia Aires, Renata F. V. Lopez, Marcilio Cunha-Filho, Guilherme M. Gelfuso, Taís Gratieri