Journal of Clinical and Experimental Ophthalmology
Open Access

Abstract

A Novel Pilocarpine Microemulsion as an Ocular Delivery System: In Vitro and In Vivo Studies

Iskender Ince, Ercument Karasulu, Halil Ates, Altug Yavasoglu and Levent Kirilmaz

Despite several disadvantages like a rapid wash out and dilution of the formulation leading to a low bioavailability, eye drops are the most commonly used dosage form for the ocular route. Due to their properties and numerous benefits, microemulsions are promising systems for topical drug delivery. The purpose of this work is to develop a suitable ocular microemulsion formulation with adequate physicochemical stability for enhancing the bioavailability of pilocarpine. Physicochemical characteristics of the microemulsion including the drug content, refractive index, conductivity, viscosity, intraocular pressure (IOP) and ocular tolerance were investigated. The ocular irritation test and the IOP lowering activity of the microemulsion were studied in New Zealand white rabbits. The developed formulation showed good physicochemical properties and a beneficial stability for six months. After microemulsion instillation into the rabbit eyes, the intraocular pressure was reduced significantly. The ocular irritation test used suggested that microemulsion formulation did not cause any significant allergies to the eye.