Topical Triamcinolone Acetonide-Loaded Liposomes as Primary Therapy for Macular Edema Secondary to Branch Retinal Vein Occlusion: A Pilot Study

Abstract

Purpose: To explore safety and therapeutic efficacy of a topical ophthalmic triamcinolone acetonide-loaded liposome formulation (TA-LF) as primary therapy in patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). Methods: Twelve eyes of 12 patients with ME secondary to BRVO were exposed to a topical instillation of 1 drop of TA-LF (TA 0.2%) 6 times a day for 12 weeks to evaluate safety and efficacy. Best corrected visual acuity (BCVA) intraocular pressure (IOP), slit lamp examination, and central foveal thickness (CFT) were analyzed at every visit. In addition, the morphology of TA-LF was analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: Patients presented a significant improvement of BCVA and CFT without significant IOP modification (P = 0.94). Treated eyes showed BCVA improvement from 40-12.05 to 64.83-15.97 letters and CFT reduction from 682.91-278.60 to 271.58-57.66 mm after 12 weeks of TA-LF therapy (P < 0.001). No adverse events, including IOP rising, were registered. SEM analysis of liposomal formulations showed that liposome (LP) size depends on its concentration. As the concentration of TA increased, the average size of LPs and the number of larger particles increased as well. TEM study displayed that LP formulation efficiently solubilizes TA crystals in nanoparticles and encapsulates them. Conclusion: LPs can function as nanocarriers of TA and they could be used as topical ophthalmic primary therapy instead of intravitreal drugs in patients with ME secondary to BRVO.

Safety and Tolerability of Topical Ophthalmic Triamcinolone Acetonide-Loaded Liposomes Formulation and Evaluation of Its Biologic Activity in Patients with Diabetic Macular Edema

“…Among these, topical liposomes (LPs) are one of the most promising strategies [19]. In fact, LPs constitute the only topical system to deliver TA into the vitreous area with clinical evidence of its effectiveness [20][21][22]. The vesicle composition of LPs share almost an indistinguishable outer structure with the cell membrane, conferring its ability to transport either hydrophilic or lipophilic drugs.…”

“…Moreover, cell viability was unaffected by TALF. Finally, the microscopic characterization of TALF using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that TALF is capable of solubilizing large TA crystals into nanoparticles and encapsulating them at the same time [22].…”

Lipid-Based Nanocarriers as Topical Drug Delivery Systems for Intraocular Diseases

“…Recently, lipid-based nanocarriers have emerged as promising nanosystems for intraocular drug delivery. For example, topical liposome-based nanosystems have demonstrated, in preclinical and early clinical studies, to be efficient to deliver triamcinolone acetonide (TA) into the vitreous and retina [ 10 , 11 ]. This technological advance in the ophthalmic pharmacology field represents the opportunity to treat multiple inflammatory and neovascular intraocular disorders avoiding or reducing the use of intravitreal injections.…”

Safety and Tolerability of Topical Ophthalmic Triamcinolone Acetonide-loaded Liposomes Formulation and Evaluation of Its Biologic Activity in Patients with Diabetic Macular Edema

“…Among these, topical liposomes (LPs) are one of the most promising strategies [19]. In fact, LPs constitute the only topical system to deliver TA into the vitreous with clinical evidence of its effectiveness [20][21][22]. LPs are biocompatible vesicles composed of a phospholipid-bilayer with structural resemblance to cell membrane, which form small spheroids that are able to carry both hydrophilic and lipophilic drugs.…”

“…Besides, cell viability was unaffected by TALF. Finally, the microscopic characterization of TALF using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), revealed that TALF is capable to solubilize large TA crystals into nanoparticles and encapsulate them at the same time [22].…”