SkyePharma's GeoMatrix underpins another new drug formulation

The new formulation of Sciele Pharma's Sular (nisoldipine), a calcium channel blocking agent for the treatment of high blood pressure, has been successfully trialled to show bioequivalence to Sciele's currently marketed product.

Using SkyePharma's patented GeoMatrix technology, the new extended release formulation has been designed to provide a lower dose of Sular for each of its current doses, the average dose of which is 10-20mg once a day for adults, and will be more readily absorbed.

US-based Sciele Pharma investor relations director Joseph Schepers was "very pleased" with the results.

"The key to the trial was to show bioequivalence and the new Sular doses will be lower than the current.

Any time we have less drugs it's always better

and I think that's the view of most doctors," he told in-PharmaTechnologist.com.

The GeoMatrix technology, originally developed by a team of researchers at the University of Pavia in Italy in the early 1980s, is applied to achieve customised levels of controlled release of specific drugs and can achieve simultaneous release of two different drugs and different rates from a single tablet.

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.

In April, the US Food and Drug Administration (FDA) accepted a filing for the extended release formulation, using GeoMatrix technology, of GlaxoSmithKline's (GSK) drug Requip (ropinirole) for the treatment of Parkinson's disease.

SkyePharma already manufactures three GeoMatrix products, Coruno (molsidomine) for Therabel, diclofenac for Ratiopharma and Madopar (levodopa and benserazide), another treatment for Parkinson's disease, for Roche.

The active ingredient in Sular is nisoldipine which inhibits the flow of calcium through the smooth muscles of the heart delaying the passage of nerve impulses and thereby relaxing blood vessels making the blood flow more easily and reducing the heart's workload.

Sular, in its current form, has been marketed in the US by Sciele since 2002 and is one of Sciele's key products with continued growth of prescriptions over the last two years.

The data from the bioequivalence study will be combined with the results from the previous clinical trial in Sciele's new Sular formulation supplemental New Drug Application (sNDA) filing.

Sciele expects to file a sNDA with the FDA by the end of the second quarter of this year with the hope of launching the drug in the first half of next year after FDA approval.