University of Porto, Faculty of Pharmacy, Drug Sciences Department, Laboratory of Pharmaceutical Technology, Portugal.
Expert Opin Drug Deliv. 2013 Sep;10(9):1223-37. doi: 10.1517/17425247.2013.796360. Epub 2013 May 21.
An ideal ophthalmic formulation is one that not only prolongs the contact time of the vehicle on the ocular surface but also slows down the drug elimination. The poor bioavailability and therapeutic response exhibited by the conventional ophthalmic solutions due to pre-corneal elimination of the drug may be overcome by the use of in situ gel forming systems. In situ gelling systems increase the viscosity by changing the pH or temperature in the pre-corneal region and lead to an increase of drug bioavailability by slowing drainage. Poloxamers are polyols with thermal gelling properties which are frequently included in ophthalmic formulations to improve the ocular bioavailability of drugs by increasing vehicle viscosity.
An overview on the unique physiological characteristics of ocular globe and the limitations and disadvantages of the conventional ophthalmic pharmaceutical formulations. Readers will appreciate the different strategies to improve the absorption of drugs in the ocular globe, especially the incorporation of poloxamers in ophthalmic formulations, understanding the main advantages of the poloxamers and also learning about the different examples of applications of these polymers in ophthalmic pharmaceutical formulations.
Poloxamers offers a new strategy to improve bioavailability and decrease the side effects induced by the systemic absorption of topically applied ophthalmic drugs.
理想的眼科制剂不仅能延长载体在眼表面的接触时间，还能减缓药物的消除速度。由于药物在角膜前被清除，传统的眼科溶液表现出生物利用度差和治疗效果不佳的问题，原位凝胶形成系统的使用可能会克服这些问题。原位凝胶系统通过改变角膜前区域的 pH 值或温度来增加粘度，从而通过减缓排出来增加药物的生物利用度。泊洛沙姆是具有热凝胶特性的多元醇，经常被包含在眼科制剂中，通过增加载体的粘度来提高药物的眼部生物利用度。
概述了眼球的独特生理特征以及传统眼科药物制剂的局限性和缺点。读者将了解改善药物在眼球吸收的不同策略，特别是泊洛沙姆在眼科制剂中的应用，了解泊洛沙姆的主要优势，并了解这些聚合物在眼科药物制剂中的不同应用实例。
泊洛沙姆为提高生物利用度和减少局部应用的眼科药物全身吸收引起的副作用提供了一种新策略。
