The approval triggers a $2m milestone payment to Skye, who will also receive low mid single digit royalties on net sales of the new Sular product.
The new extended release formulation was designed to provide a lower dose of Sular for each of its current doses and be more readily absorbed. The average adult dose of the existing product is 10-20mg.
The FDA has approved all four dosage strengths of the new formulation, which uses SkyePharma's patented GeoMatrix technology to achieve the drug's controlled release profile.
The controlled release is achieved by constructing a tablet made of two basic components, hydroxypropyl methycellulose (HPMC) and one or more barrier layers. The HPMC core contains the drug's active ingredient and the combination of barrier layers control the surface area diffusion of the drug (or drugs) out of the core.
The combination of layers, each with different rates of swelling, gelling and erosion, is responsible for the rate of drug release within the body. When first swallowed, for example, the drug concentration is high but the surface area low. As time progresses the core swells, and the surface area increases to make up for the decrease in drug concentration.
According to SkyePharma, one of the major benefits of the GeoMatrix technology is its ability to be easily incorporated into the production line. The firm claims that GeoMatrix tablets can be manufactured by readily available equipment that can be integrated into widely-used pharmaceutical processes, thus giving firms more control over their own production activities.
SkyePharma will, however, be manufacturing the new Sular product itself at its Lyon manufacturing facility.
The existing Sular formulation is one of Sciele's key products, with healthy growth in prescriptions for the calcium channel blocker. The two firms joined forces in May 2006 to develop a revamped Sular product with an improved pharmacokinetic profile, intended to replace the current formulation and expand the drug's market opportunity.
Launch of the new product is expected during the first quarter 2008.
