New drug delivery system aims to increase tissue penetration

Alameda, CA-InSite Vision has introduced a next-generation delivery system (DuraSite 2) as a platform for emerging ophthalmic drugs.

The new platform, based on the company’s original delivery system (DuraSite), is designed to permit increased tissue penetration for topically delivered ocular drugs, with the aim of improved efficacy and dosing convenience. It incorporates a cationic polymer to achieve sustained and enhanced ocular delivery of drugs. Both the original system and its successor are formulated with the non-steroidal anti-inflammatory drug ketorolac.

The company also announced top-line data from a large-scale comparative study that in an animal model demonstrated improved drug retention and tissue penetration for the new system compared with its predecessor. In the three-arm preclinical pharmacokinetic study, formulations of ketorolac with the new system achieved a concentration in the aqueous humor of the eye of more than two and four times that of ketorolac with the older system or ketorolac alone, respectively. Further, no indication of eye irritation was evident using the newer platform, according to the company.

The new delivery system “has surpassed our expectations, achieving multifold tissue penetration and positive safety results in a well-designed, large-scale preclinical study,” said Lyle Bowman, PhD, vice president of development of InSite Vision. “We believe [it] could be critical in optimizing the profile of approved and future ocular drugs, extending the drug retention on the eye and reducing dosing frequency and the amount of drug needed to achieve efficacious results.”

The company filed the intellectual property surrounding the new system in early 2009, meaning that its potential patent life-as well as increased protection for all drugs formulated with the system-extends into 2029, he added. Patent applications were submitted in 2009 in the United States and Europe and were published in 2010. Both patents are pending issuance.

The original delivery system is used in two commercial products for the treatment of bacterial eye infections, azithromycin (AzaSite, Merck) and besifloxacin (Besivance, Bausch + Lomb). InSite Vision said it plans to use the new platform in all its future pipeline product candidates. Via a licensing program, the company intends to provide to industry partners product access through both exclusive and non-exclusive licensing and/or commercialization agreements.

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