Abstract Ocular infection caused by Mycobacterium tuberculosis affected an estimated 0.1−0.2 million people in the year 2018 worldwide and may result in irreversible loss of vision if not treated properly. Despite this significant figure, the only therapy used to date is the oral administration of anti-tuberculosis drugs substances, mainly rifampicin (Rif), which presents severe adverse effects. Besides, the blood-retinal barrier (BRB) impairs the drug substance bioavailability into the eye. Thus, it is needed urgently an ophthalmic preparation to treat this infection. Cationic nanoemulsion (NE) has been considered a major shift towards an effective ophthalmic drug delivery. To the best of our knowledge, our study presents the first ophthalmic cationic nanoemulsion for the treatment of ocular tuberculosis. In our study, a Rif-loaded cationic nanoemulsion with specific surface modification employing chitosan (CS) and polymyxin B (PB) was developed successfully. Rif-NE + CS and Rif-NE + PB preparations exhibited particle size of approximately 150 nm, and zeta potential values of +51.3 mV and +5.5 mV, respectively. in vitro assessment of mucoadhesion test indicated electrostatic interaction of cationic nanoemulsions with negative charged mucin, which may improve the preparation efficacy by increasing its residence time on the organ of vision. In vitro antimicrobial activity showed that the high-pressure homogenization (HPH) method and surface modification process did not affect the antimicrobial efficacy of Rif. These findings may enable a promising alternative line of ophthalmic products for the management of ocular tuberculosis with potential longer interval between administration.

中文翻译：

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阳离子利福平纳米乳治疗眼结核

摘要 结核分枝杆菌引起的眼部感染在 2018 年影响了全球约 1-20 万人，如果治疗不当可能会导致不可逆转的视力丧失。尽管有这个显着的数字，但迄今为止唯一使用的治疗方法是口服抗结核药物，主要是利福平 (Rif)，它具有严重的副作用。此外，血-视网膜屏障 (BRB) 会损害药物进入眼睛的生物利用度。因此，迫切需要一种眼科制剂来治疗这种感染。阳离子纳米乳剂 (NE) 被认为是向有效眼科药物递送的重大转变。据我们所知，我们的研究提出了第一种用于治疗眼结核的眼科阳离子纳米乳剂。在我们的研究中，使用壳聚糖 (CS) 和多粘菌素 B (PB) 进行特定表面改性的 Rif 负载阳离子纳米乳液已成功开发。Rif-NE + CS 和 Rif-NE + PB 制剂的粒径约为 150 nm，zeta 电位值分别为 +51.3 mV 和 +5.5 mV。黏膜粘附试验的体外评估表明阳离子纳米乳与带负电荷的黏蛋白发生静电相互作用，这可能通过增加其在视觉器官上的停留时间来提高制剂的功效。体外抗菌活性表明，高压均质（HPH）方法和表面改性工艺不影响 Rif 的抗菌功效。