Abstract
Purpose::
Commercial formulation development to obtain a stable, preserved, aqueous eye drop of 1% azithromycin in DuraSite (AzaSite; InSite Vision, Alameda, Ca).
Methods::
A novel method for the formulation of azithromycin in an ophthalmic delivery system was developed using DuraSite, an ophthalmic drug delivery system. The robustness of the resulting formulation was evaluated in stability studies at 5° and 25°C. Preservative efficacy was also evaluated.
Results::
The DuraSite formulation of 1% azithromycin is a low viscosity gel-forming eye drop that is soluble in the aqueous tear fluid. The formulation is stabile at room temperature for 9-12 months. Stability at 5°C has been measured to be a minimum of 36 months. The sterile formulation is preserved with benzalkonium chloride sufficient to pass USP Preservative Efficacy requirements.
Conclusions::
Azithromycin is a well-known azalide antibiotic that is available in intravenous (iv) and oral dosing forms. Its use as a topical anti-infective in ophthalmology is limited to non-preserved research batches created from hydration of the iv form. DuraSite is a proprietary drug delivery system that forms a stable water soluble solution with azithromycin. The mucoadhesive properties of DuraSite provide a higher bioavailability to the conjunctival tissues than a conventional eye drop. The enhanced drug retention times relative to conventional drops leads to higher drug tissue levels and a reduced dosing frequency in the eye.
Keywords: antibiotics/antifungals/antiparasitics • drug toxicity/drug effects • conjunctivitis