By Frank Chrzanowski, Ph.D.

Drug delivery systems for controlled release have fascinated pharmaceutical development organizations and entrepreneurs because they offer opportunities for line extensions of existing patent expiring immediate release dosage forms. This strategy has been applied successfully in a number of products such as Paxil® paroxetine, Coreg® carvedilol, and Adderall® mixed amphetamine salts, just to name a few. In addition to conventional controlled release methods, a number of novel and patented systems have emerged offering extended non-substitutable product life due to the patent length offered by the technology. The ALZA osmotic delivery systems were among the first and their strategy in offering extended patent protection to controlled release drug products became the model for many new entrepreneurial organizations. These drug delivery system companies depend upon their technology rather then upon the discovery and development of new products from new chemical entities. I have often wondered whether this tactic is sustainable over the long term.

In years past, the waiting list to get a new project in at ALZA was estimated at two years. Today, ALZA has no R&D organization, most likely due to a lack of new patents. It continues the manufacture of some osmotic delivery system products, but has not initiated new projects in several years. In discussing the complexity of the ALZA osmotic drug delivery system with a generic competitor of their technology, the competitor claimed to have more of the manufacturing equipment than ALZA did. Not a good sign.

In similar fashion at least one entrepreneurial company opted to develop a patent protected pulsatile delivery system for a penicillin. This penicillin has a long history of safety and success in treating infections and is usually dosed in three-times-daily fashion. At great expense, this company developed a once a day dosage form that delivered three pulses of the penicillin. A remarkable feat, but was it marketable? The competition to this product consisted of an overwhelming number of generic companies that offered their product for sale at a much lower cost. Insurance companies saw no advantage to the more expensive, more convenient, once a day dosage form when compared to the less expensive generic product. Additional pulsatile delivery products were planned by this company; however, it appears that development is delayed if not discontinued. An additional question would have remained for this company and others like it: how long could it continue to develop novel patent protected delivery systems before it ran out of patentable ideas?

I am sure that readers can enumerate many other examples of novel patented drug delivery systems that are marketed for line extensions of existing patent expiring compounds. However, the question that I ask is, for how long can such a company exist before it runs out of patentable ideas?

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Frank Chrzanowski, Ph.D. is a Pharmaceutical Development and CMC issues Consultant and Patent Litigation Expert Witness, and the moderator of Contract Pharma’s annua Contracting & Outsourcing conference &tabletop exhibition. He can be reached by e-mail at [email protected] or phone at 856-983-7996. His website is comcast.net/~frankchrzan