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Honey-based medical dressing can be patented

23 January 2012

A patent for a honey-based medical dressing was not invalid on the ground of obviousness, appeal judges have ruled.

The court heard that honey has been used to heal wounds since ancient times. Not only did the ancient Egyptians use honey in this way, described in a papyrus dating to 1500BC, but there are Sumerian clay tablets 500 years older, which record the same thing.

In the UK, it was not until the 1990s that conventional medicine rediscovered the healing properties of honey, based on a growing body of evidence that it possessed anti-microbial and anti-inflammatory properties.

Delivering the leading judgment in Apimed Medical Honey v Brightwake [2012] EWCA Civ 5, Lord Justice Kitchin said the patent involved the “use of honey in medical dressings and that the honey is modified with a gelling agent, resulting in compositions in the form of a flexible sheet or a pliable putty which can be used as a wound covering”.

Kitchin LJ said that sodium alginate was the gelling agent used. He said the trial judge at the Patents County Court, Judge Fysh QC, found that alginate dressings were a matter of common general knowledge.

“The first, called Sorbsan, was made of calcium alginate, and the second, called Kaltostat, was made of sodium-calcium alginate,” Kitchin LJ said.

“Both were made in the form of felts, that is to say layers of randomly deposited fibres. By December 1999 these dressings were not only widely available in hospitals and clinics but had largely replaced the use of cotton gauze in the treatment of highly exuding wounds.”

Kitchin LJ said the trial judge identified the only difference between the state of the art and the inventive concept of the claim as being the alginate dressings.

Judge Fysh concluded that it was obvious to use these dressings instead of gauze and that all the patent’s claims “were obvious in the light of that disclosure”.

Kitchin LJ went on: “In my judgment it is clear that the judge fell into error at this point. The only dressings which he had found formed a part of the state of the art were the calcium alginate and sodium-calcium alginate dressings sold under the brand name Sorbsan and Kaltostat respectively.”

However, the lord justice said the “real difference” between the state of the art and the patent was “having the idea of discarding such a dressing altogether and, instead, using a gelling agent such as particulate sodium alginate to increase the viscosity of the honey to such a degree that it could be rolled into a sheet or formed into a putty without the need for any dressing at all”.

Kitchin LJ said Brightwake’s expert, Professor White, “simply stated that an obvious way to address the problem of application and retention was to make the honey thicker, to use for this purpose a thickening agent and that alginate was an obvious candidate because it was commonly used in the wound environment”.

But Lord Justice Kitchin said the only way it was used in the wound environment was in the form of the calcium alginate or sodium-calcium alginate pads, which did not act as a gelling agent.

He dismissed Brightwake’s appeal. Lord Justices Toulson and Etherton agreed.

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