A more efficient ocular delivery system of triamcinolone acetonide as eye drop to the posterior segment of the eye

Abstract

As a leading cause of vision impairment of the retina, macular edema (ME) has one of the highest clinical demands for treatment. Current treatment of ME relies heavily on invasive techniques resulting in complications and poor patient compliance. To enhance the efficiency of triamcinolone acetonide as eye drop to the posterior segment of the eye, we developed and characterized a novel formulation, namely, triamcinolone acetonide chitosan-coated liposomes (TA-CHL), prepared by the calcium acetate gradient method with some modifications. TA-CHL provided the mean particle size of 135.46 ± 4.49 nm and high entrapment efficiency (90.66 ± 3.21%), exhibited a sustained release profile, excellent physical stability, and no significant toxicity on cornea, conjunctiva, and retina. Optical coherence tomography system (OCT) was used to detect pharmacokinetics of CHL in vivo , indicating that CHL had good potency for drug delivery. Cellular uptake experiments showed CHL had the higher transduction efficiency into HCEC and ARPE-19 than liposomes. TA-CHL was shown to be potentially effective eye drop to contribute to the posterior segment of the eye.

Novel Triamcinolone Acetonide-Loaded Liposomal Topical Formulation Improves Contrast Sensitivity Outcome After Femtosecond Laser-Assisted Cataract Surgery

“…Recently, in animal models, Jin Li et al (2019) validated that eye drops containing TA-loaded liposomes are an efficient method to deliver this drug into the posterior segment of the eye, 28 which supports previous findings published by our group. 26 Even though Li et al reached higher TA entrapment efficiency in their TA-loaded liposomes prepared through the calcium acetate gradient method, in our experience, this characteristic does not compromise the therapeutic activity of TA-LF.…”

“…Different reports have proved that liposomes are suitable vehicles for the delivery of steroids into the retina when topically applied. 26,28 Besides, the pharmacokinetic study of TA-LF validated that this formulation was capable of efficiently releasing TA into the vitreous and the retina when topically applied in rabbits. 26 In addition, it is important to emphasize that components of TA-LF formulations other than liposomes can increase the efficiency of the delivery of TA into the vitreous and the retina.…”

“…We hypothesized that the improvement in CS in the TA-LF group over the P + N group had to do with the ability of liposomes to efficiently deliver steroid into the retinal tissue. 26,28 It has been established that the adequate function of photoreceptors is crucial for CS 29,30 and it is known that macular edema causes the dysfunction of foveal photoreceptor cells (reduced directional sensitivity of photoreceptor cells). 31 In contrast, steroids could improve the function of photoreceptors and protect them from damage through the activation of the protein kinase B (AKT) signaling pathway.…”

“…Moreover, the pharmacokinetic study on TA-LF validated that this formulation was capable of efficiently releasing TA into the vitreous and the retina when topically applied in rabbits. 26 Finally, multiple efforts have been made to generate a topical formulation for the delivery of TA into the posterior segment of the eye using different delivery strategies such as those that include liposomes and lipid nanoparticles 26,28,72,73 ; however, only TA-LF has been proved in clinical assays, where its efficiency and safety profiles have satisfactorily been demonstrated. 27 Once again, in this study, we observed that TA-LF is well tolerated and holds an acceptable safety profile, with no ocular AEs.…”

Chitosan and its Derivatives for Ocular Delivery Formulations: Recent Advances and Developments

“…Li et al encapsulated triamcinolone acetonide, which is an intermediate-acting glucocorticoid applied in inflammatory, edematous, and angiogenic ocular diseases, in liposomes, and the resulting NPs were further coated with CS [294]. The coating of NPs resulted in a slight increase of the size, i.e., from 108 to 135 nm, while the ζ-potential was inverted from −10 to +18 mV.…”