Chitosan coated liposomes (CCL) containing triamcinolone acetonide for sustained delivery: A potential topical treatment for posterior segment diseases

Drug delivery to the posterior eye is limited by epithelial and mucosal barriers limiting the topical administration of drugs leading to invasive modes of repeated long-term painful administration of drugs. Several constructs of liposomes have been prepared to counter this challenge yet are often limited by size and surface charge resulting in poor encapsulation efficiency, low retention time, and poor permeability. In the present study, chitosan coated liposomes (CCL) were prepared to address these challenges. Conventional liposomes encapsulating Triamcinolone Acetonide (TA) were compared with their chitosan coated counterpart for drug loading and release studies. CCL showed a higher encapsulation efficiency (74%), and a highly positive surface charge (+41.1Mv), increased retention time and sustained release. Choroidal neovascularization (CNV) rat models were generated to assess the efficiency of CCLs as nanocarriers in drug delivery. Significant amount of TA was found to be present and retaining in the eye after fifteen days of treatment with CCL, as shown by HPLC analysis. The results showed successful penetration of the construct via corneal mucosal barrier and its accumulation in vitreous body. The analysis shows that this chitosan based liposomal construct can be employed as a potential topical delivery system for treating posterior segment diseases.