在各种药物输送途径中,眼部药物递送领域是过去10-20年来药学科学家面临的最有趣和最具挑战性的努力之一。作为一个孤立的器官,从药物递送的角度来看,研究眼睛是非常困难的。尽管有这种限制,已经进行了改进,目的是将药物在生物相内维持更长的时间。眼部治疗中的主要问题是在作用部位获得最佳药物浓度。为了实现有效的眼科治疗,足够量的活性成分必须被递送并保持在眼睛内。最常用的剂型,即,眼部溶液,眼药膏,眼部凝胶,和眼悬浮液的有效性受到几个限制,导致较差的眼部生物利用度。增粘剂的眼科用途,渗透促进剂,环糊精,前药方法,和眼部插入物,和现成的药物载体系统以及它们在眼科药物递送中的应用对于改善眼部生物利用度是常见的。在这些水凝胶(刺激敏感)系统中,响应于生理(温度,pH值和生物体流体中离子的存在,酶底物)或其他外部(电流,光)刺激。它们有助于将药物的角膜前停留时间增加到足以使眼睛递送的药物表现出其最大生物学作用的程度。这种创新的眼科递送方法的概念是减少全身性副作用,并且用较低剂量的药物产生更显著的效果。本文描述了水凝胶系统在眼科药物递送中的优点和使用刺激敏感。
Amongst the various routes of drug delivery, the field of ocular drug delivery is one of the most interesting and challenging endeavors facing the pharmaceutical scientist for past 10-20 years. As an isolated organ, eye is very difficult to study from a drug delivery point of view. Despite this limitation, improvements have been made with the objective of maintaining the drug in the biophase for an extended period. A major problem in ocular therapeutics is the attainment of an optimal drug concentration at the site of action. To achieve effective ophthalmic therapy, an adequate amount of active ingredient must be delivered and maintained within the eye. The most frequently used dosage forms, i.e., eye solution, eye ointments, eye gels, and eye suspensions are compromised in their effectiveness by several limitations leading to poor ocular bioavailability. Ophthalmic use of viscosity-enhancing agents, penetration enhancers, cyclodextrins, prodrug approaches, and ocular inserts, and the ready existing drug carrier systems along with their application to ophthalmic drug delivery are common to improve ocular bioavailability. Amongst these hydrogel (stimuli sensitive) systems are important, which undergo reversible volume and/or sol-gel phase transitions in response to physiological (temperature, pH and present of ions in organism fluids, enzyme substrate) or other external (electric current, light) stimuli. They help to increase in precorneal residence time of drug to a sufficient extent that an ocularly delivered drug can exhibit its maximum biological action. The concept of this innovative ophthalmic delivery approach is to decrease the systemic side effects and to create a more pronounced effect with lower doses of the drug. The present article describes the advantages and use stimuli sensitive of hydrogel systems in ophthalmic drug delivery.