Development and in vitro/in vivo evaluation of thermo-sensitive in situ gelling systems for ocular allergy

Ocular allergy is one of the most common disorders of the eye surface. Following diagnosis this condition is typically treated with preparations containing antihistamines. However, anatomy of the eye and its natural protective mechanisms create challenges for ocular drug delivery. Rapid elimination of antihistamine substances due to short residency times following application can lead to insufficient treatment of ocular allergies. With this in mind, the aim of this study was to prepare a controlled ocular delivery system to extend the retention time of olopatadine hydrochloride (OLO) and in doing so to reduce the need for frequent application. We developed extended-release ocular in situ gelling systems for which in vivo retention times were determined in sheep following in vitro characterization and cytotoxicity studies. In vivo results were then compared to commercially available Patanol eye drops. the transparent gels formulated using appropriate amounts of polymers and having longer ocular retention times appear to be a viable alternative to commercially available eye drops.

New dosage forms for ocular administration / 中国药学杂志

Topical ocular medication is commonly used for eye diseases treatment.In view of low bioavailability and poor efficacy of traditional ocular preparations, the development of novel ocular drug delivery systems has become a great challenge in pharmaceutics.In recent years, nano preparations have been widely used for ocular drug delivery systems. At present, several nanocarriers, such as polymeric micelles, nanoparticles, nanosuspension, liposomes, emulsion, and dendritic polymers have been developed for ocular drug delivery.There are some other new dosage forms, such as in-situ gelling systems, implants, contact lenses, and microneedles are also under continuous research. The aim of development of these new dosage forms is to improve the drugs' ocular bioavailability and therapeutic effects.In this paper, the development in these areas in recent years are reviewed in order to provide reference for the development of new ocular drug delivery systems.