The effectiveness and uses of chitosan nanoparticles (CNPs) in drug delivery systems are examined in this work. Important results include the improved drug encapsulating efficiency: CNPs showed up to 90% encapsulation for different therapeutic agents. Furthermore, the research shows that CNPs provide extended-release patterns, greatly enhancing medication bioavailability especially for hydrophobic compounds. One interesting outcome was the greater drug stability in acidic surroundings, which are common in the stomach, where CNPs turn into a gel and later inflate in the intestine where the drug is released. Moreover, CNPs showed a 2-3-fold improvement in the absorption of encapsulated pharmaceuticals relative to traditional formulations, therefore indicating their capacity to overcome the problems of low oral bioavailability. These nanoparticles' pH-sensitive character produced a 50-70% increase in drug release at certain pH values, hence maximizing therapeutic results. Significantly less systemic toxicity was seen in the in vivo tests, and at therapeutic dosages there were no noted side effects. Histological study confirmed the biocompatibility and non-toxicity of CNPs, therefore attesting their fit for long-term usage. These results highlight the great potential of CNPs in providing effective, focused, continuous drug release, hence improving therapeutic effectiveness and patient compliance.

Keywords: biocompatibility; chitosan; drug delivery; ocular drug delivery.

本文研究了壳聚糖纳米颗粒（CNPs）在药物递送系统中的有效性和用途。重要成果包括改进的药物包封效率：CNPs 对不同治疗剂的最大包封率可达90%。此外，研究表明 CNPs 可提供缓释模式，显著提高特别是对于疏水性化合物的药物生物利用度。有趣的结果之一是，在胃部常见酸性环境下，药物稳定性更强，此时 CNPs 会形成凝胶状，并在肠道中膨胀并释放药物。此外，CNPs 显示出相对于传统配方而言，封装药物吸收率提高了2-3倍，因此表明其能够克服口服生物利用度低的问题。这些纳米颗粒的 pH 敏感特性导致在某些pH值下药物释放增加了50-70%，从而最大化了治疗效果。体内测试中观察到显著较低的全身毒性，在治疗剂量下未发现副作用。组织学研究表明 CNPs 具有生物相容性和无毒性，因此证实其适合长期使用。这些结果突显了 CNPs 在提供有效、集中、持续药物释放方面的巨大潜力，从而提高治疗效果和患者的依从性。

关键词：生物相容性；壳聚糖；药物递送；眼部药物递送。