This paper presents a novel nanoformulation for sustained-release delivery of dexamethasone (DEX) to the ocular posterior segment using a Laponite (LAP) carrier—DEX/LAP 1:10 w w⁻¹ formulation; 10 mg ml⁻¹. In vivo ocular feasibility and pharmacokinetics after intravitreal (IV) and suprachoroidal (SC) administration in rabbit eyes are compared against IV administration of a DEX solution (1 mg ml⁻¹). Thirty rabbit eyes were injected with the DEX/LAP formulation (15 suprachoroid/15 intravitreous). Ophthalmological signs were monitored at day 1 and at weeks 1–4–12–24 post-administration. Three eyes per sample time point were used to quantify DEX concentration using high-performance liquid chromatography-mass spectrometry. The ocular tissues’ pharmacokinetic parameters (lens, vitreous humour, choroid-retina unit and sclera) were studied. DEX/LAP was well tolerated under both administration methods. Peak intraocular DEX levels from the DEX/LAP were detected in the vitreous humour after both deliveries soon after administration. The vitreous area under the curve was significantly greater after both DEX/LAP deliveries (IV: 205 968.47; SC: 11 442.22 ng g⁻¹ d⁻¹) than after IV administration of the DEX solution (317.17 ng g⁻¹ d⁻¹). Intravitreal DEX/LAP delivery extended higher vitreous DEX levels up to week 24 (466.32 311.15 ng g⁻¹). With SC delivery, DEX levels were detectable in the choroid-retina unit (12.04 20.85 ng g⁻¹) and sclera (25.46 44.09 ng g⁻¹) up to week 24. This study demonstrated the intraocular feasibility of both SC and IV administration of the DEX/LAP formulation. The LAP increased the intraocular retention time of DEX when compared with conventional solutions. DEX/LAP could be considered a biocompatible and useful sustained-release formulation for treating posterior-pole eye diseases.

^{本文介绍了一种新型纳米制剂，用于使用 Laponite (LAP) 载体——DEX/LAP 1:10 ww -1}制剂将地塞米松 (DEX) 缓释至眼后节；10毫克毫升^-1。将兔眼玻璃体内 (IV) 和脉络膜上 (SC) 给药后的体内眼部可行性和药代动力学与 DEX 溶液 (1 mg ml ^{-1 ) 的 IV 给药进行比较}）。三十只兔眼注射了 DEX/LAP 制剂（15 个脉络膜上腔/15 个玻璃体内）。在给药后第 1 天和第 1-4-12-24 周监测眼科体征。每个样品时间点三只眼睛用于使用高效液相色谱-质谱法量化 DEX 浓度。研究了眼组织的药代动力学参数（晶状体、玻璃体液、脉络膜-视网膜单位和巩膜）。DEX/LAP 在两种给药方法下均具有良好的耐受性。在两次分娩后不久，在玻璃体液中检测到来自 DEX/LAP 的眼内 DEX 峰值水平。两次 DEX/LAP 分娩后，曲线下的玻璃体面积显着增加（IV：205 968.47；SC：11 44​​2.22 ng g ^-1 d ^-1) 比静脉注射 DEX 溶液后 (317.17 ng g ^-1 d ^-1 )。玻璃体内 DEX/LAP 递送将较高的玻璃体 DEX 水平延长至第 24 周 (466.32 311.15 ng g ^-1 )。^{通过 SC 分娩，直到第 24 周，在脉络膜视网膜单位 (12.04 20.85 ng g -1} ) 和巩膜 (25.46 44.09 ng g ^-1 )中可检测到 DEX 水平。这项研究证明了 SC 和 IV 给药的眼内可行性DEX/LAP 公式。与传统溶液相比，LAP 增加了 DEX 的眼内保留时间。DEX/LAP 可以被认为是一种生物相容且有用的缓释制剂，用于治疗后极眼部疾病。