InSite Vision, an ophthalmic therapeutics and drug delivery company, has developed an antibiotic eye drop which stays on the surface of the eye much longer than conventional drops, using the patented DuraSite drug delivery vehicle.
AzaSite (azithromycin ophthalmic solution) 1 per cent treatment of bacterial conjunctivitis ("pinkeye"), was launched in the US yesterday, marketed by Inspire Pharmaceuticals. Using the DuraSite drug delivery vehicle, AzaSite offers the fewest number of doses for the eye condition because of the drug's ability to stay on the eye surface longer.
While up to 90 per cent of most eye drops are lost in the first 15 to 30 seconds after administration, resulting in frequent dosing, AzaSite has been designed to contain a non-toxic, biocompatible and biodegradable polymer that can maintain therapeutic doses of a drug on the eye's surface for up to six hours.
The polymer forms a matrix, within which the drug particles are suspended.
The drug is released in the aqueous environment of the eye and as the eye lids blink a layer of the formulation is exposed to the cornea and conjunctiva.
"AzaSite is a welcome addition to the treatment regimen for bacterial conjunctivitis," University of Pittsburgh School of Medicine assistant professor of ophthalmology Francis Mah said in a statement regarding the launch of the product.
"In Phase III clinical trials, AzaSite had excellent bacterial eradication rates against the three most common causes of bacterial conjunctivitis with tolerability similar to placebo.
This, combined with a convenient dosing schedule of nine drops over the course of a week, makes AzaSite an exciting new product for both patients and parents."
The recommended dose for AzaSite is one drop twice-a-day for two days, followed by one drop once-a-day for the next five days, a total of nine drops per affected eye.
This is compared to conventional treatments which recommend one drop three times-a-day for seven days per affected eye.
In February 2007, Inspire Pharmaceuticals licensed the rights from InSite Vision to commercialise AzaSite in the US and Canada.
Inspire estimates revenues from US sales of AzaSite to reach $30m to $45m in 2008.
InSite Vision is developing a number of other anti-infective products combining azithromycin and DuraSite, including: AzaSite Plus, a product candidate being developed that also contains an anti-inflammatory steroid for treatment of blepharitis, a bacterial infection and inflammation condition of the eye; AzaSite Otic, a product candidate under development for the treatment of bacterial ear infections; and AzaSite Xtra, a product candidate under development for the treatment of ocular infection.
Azithromycin is a semi-synthetic antibiotic derived from erythromycin and has been available in an oral form as Zithromax from Pfizer since 1992.