Department of Pharmaceutics, SLT Institute of Pharmaceutical Sciences, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, India.
Curr Eye Res. 2021 Dec;46(12):1844-1852. doi: 10.1080/02713683.2021.1942071. Epub 2021 Jun 28.
: The aim of this study was to formulate brimonidine tartrate loaded phase transition microemulsions (PMEs), which undergo phase transition from water in oil (W/O) microemulsions to liquid crystalline (LC) and then oil in water (O/W) microemulsions after instilled into the eye and prolong the precorneal residence time and ocular bioavailability for the effective treatment of glaucoma.: The pseudo-ternary phase diagram was developed and various PMEs were prepared using Tween 80 and Span 80 with isopropyl myristate and water. Globule size and shape, physicochemical parameters, and drug release of PMEs were studied. The anti-glaucoma efficacy of optimized PMEs was studied in an experimental rabbit eyes model and compared with marketed formulation (MF).: Globule size of PMEs was found less than 200 nm, which was confirmed by both dynamic light scattering technique and Transmission Electron Microscopy. Physicochemical properties such as pH, refractive index, percentage transparency, viscosity and conductivity were also found in the acceptable ranges. release studies of PMEs exhibited sustained release property. permeation study also supported the enhanced drug flux through cornea from PMEs as compared with MF. In pharmacodynamic study, a greater reduction in intraocular pressure was seen in PMEs as compared to MF.: PMEs as ocular drug delivery system offer a promising approach to enhance the corneal contact, higher permeation and prolonged precorneal retention time in the eye leading to sustained drug release, enhanced bioavailability and patient compliance.
: 本研究旨在制备酒石酸溴莫尼定载相转变微乳（PMEs），这些微乳在注入眼睛后会从油包水（W/O）微乳转变为液晶（LC），然后再转变为水包油（O/W）微乳，从而延长在角膜前的停留时间和眼部生物利用度，以有效治疗青光眼。通过伪三元相图，使用吐温 80 和司盘 80 与肉豆蔻异丙酯和水制备了各种 PMEs。研究了 PMEs 的粒径和形状、物理化学参数和药物释放。并在实验性兔眼模型中研究了优化的 PMEs 的抗青光眼疗效，并与市售制剂（MF）进行了比较。通过动态光散射技术和透射电子显微镜证实，PMEs 的粒径小于 200nm。此外，pH 值、折射率、透光率百分比、粘度和电导率等物理化学性质也在可接受范围内。释放研究表明 PMEs 具有缓释性能。渗透研究也支持 PMEs 通过角膜的药物通量增加，与 MF 相比。在药效学研究中，与 MF 相比，PMEs 可显著降低眼内压。: 作为眼部给药系统，PMEs 提供了一种有前途的方法，可以增强角膜接触、提高渗透性和延长在眼睛中的角膜前滞留时间，从而实现药物的持续释放、提高生物利用度和患者依从性。
