Department of Pharmaceutics, Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Curr Eye Res. 2013 Mar;38(3):342-52. doi: 10.3109/02713683.2012.745879. Epub 2012 Dec 7.
Dexamethasone (DXN) is an effective anti-inflammatory drug in the treatment of acute and chronic eye disease such as uveitis. However, its low aqueous solubility limits its clinical usefulness. The purpose of this study was to investigate the mucoadhesive chitosan-coated cationic microemulsions (CH-MEs) for ophthalmic delivery of DXN to treat uveitis.
The pseudo-ternary phase diagrams were developed and various MEs were prepared using isopropyl myristate as oil, Tween 80 as a surfactant, propylene glycol as a co-surfactant and distilled water. MEs were prepared and coated with chitosan by the dropwise addition of chitosan solution in the ME dispersion. Physicochemical parameters (globule size, zetapotential, drug content, viscosity, refractive index and pH), mucoadhesive properties and the in vitro release of MEs were studied. The in vivo efficacy of prepared formulations and the marketed drug solution were studied by administering them topically to endotoxin-induced uveitis rabbit model.
All formulations displayed an average globule size less than 200 nm and a positive surface charge. The developed CH-MEs showed acceptable physico-chemical behavior, good mucoadhesive properties, good stability for three months and exhibited sustained drug release. In vivo studies in rabbit eye showed a marked improvement in the anti-inflammatory activity of mucoadhesive CH-ME-treated eye compared with a marketed suspension formulation in a uveitis-induced rabbit eye model.
The developed CH-MEs are a viable alternative to conventional eye drops for its ability to enhance bioavailability through its longer precorneal residence time and its ability to sustain the release of the drug.
地塞米松（DXN）是一种有效的抗炎药物，可用于治疗急性和慢性眼部疾病，如葡萄膜炎。然而，其低水溶性限制了其临床应用。本研究旨在探讨壳聚糖包覆的阳离子微乳（CH-ME）作为眼部递药系统用于治疗葡萄膜炎的可行性。
采用伪三元相图法，以肉豆蔻酸异丙酯为油相，吐温 80 为表面活性剂，丙二醇为助表面活性剂，蒸馏水为水相，制备了各种 ME。通过将壳聚糖溶液逐滴滴加到 ME 分散体中，对 ME 进行包衣。研究了 ME 的物理化学参数（粒径、Zeta 电位、药物含量、黏度、折射率和 pH 值）、黏膜黏附性能和体外释放情况。通过向内毒素诱导的兔葡萄膜炎模型局部给予制备的制剂和市售溶液，研究了它们的体内疗效。
所有制剂的平均粒径均小于 200nm，表面带正电荷。所开发的 CH-ME 表现出可接受的物理化学行为、良好的黏膜黏附性能、良好的三个月稳定性，并表现出持续的药物释放。兔眼体内研究表明，与市售混悬剂相比，黏膜黏附 CH-ME 处理的眼睛在兔葡萄膜炎模型中具有更好的抗炎活性。
所开发的 CH-ME 是传统滴眼液的一种可行替代品，因为它能够通过延长在眼前房的停留时间和持续释放药物来提高生物利用度。
