A Sweet Decision on Obviousness

This Kat admits that puzzling over the implications of difficult leading cases is intellectually stimulating, but sometimes exhausting. Today’s decision of the Court of Appeal in Apimed Medical Honey Ltd v Brightwake Ltd [2012] EWCA Civ 5 is refreshingly straightforward. While Kitchin LJ, writing for the Court of Appeal, overruled Judge Fysh QC [2011] EWPCC 2, who had held the patent invalid for obviousness, there is no general principle at issue.

The formula for honey as a wound dressing?

Apimed’s patent, EP(UK) 1,237,561, related to the use of honey for the treatment of wounds. This use for honey has been known since ancient times – the patent itself says that this use is recorded in 4000 year old Sumerian clay tablets. It has recently been discovered that this was not superstition on the part of the ancients, and honey does indeed have anti-microbial properties. The problem is that honey is liquid at body temperature, and so is difficult to retain at the wound site, and is liable to be diluted by the moisture exuded by the wound. The patent solved this problem by teaching that a “gelling agent” should be used so that the honey would gel into a sheet or putty which could then by applied directly to the wound. The particular gelling agent emphasized in the examples was sodium alginate. The closest prior art was an article by the inventor himself which taught the use of honey impregnated into a dressing of calcium alginate or sodium-calcium alginate. Both of these types of dressings were commonly used in hospitals in place of cotton gauze. Judge Fysh, in a couple of briefly reasoned paragraphs, found the use of sodium alginate obvious over this prior art.

However, as the Kitchin LJ emphasized, despite the similarity in composition, calcium alginate and sodium-calcium alginate are not gelling agents. They are fibrous felts, like cotton. They are insoluble in honey, and do not cause the honey to gel or become more viscous. Instead the honey is retained in the interstices of the felt material. Sodium alginate, in contrast, dissolves into the honey and causes its viscosity to increase. There was some debate as to whether it forms a true gel, but it does in any event allow the honey / alginate compound to be formed into sheets and applied to the wound. Consequently, as Kitchin J explained

The real difference between the [prior art] and the inventive concept of claim 1 of the Patent lay not in the adoption of a calcium or sodium-calcium dressing in place of a gauze dressing but rather in 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 J held that the failure to correctly identify the differences between the prior art and the invention was an error of principle, and he went on to conclude that the claims at issue were not obvious.

As a postscript, the defendant Brightwake had prevailed at trial on the issue of infringement, and Apimed appealed solely to establish the validity of its patent. In accordance with the guidance given in Halliburton Energy Services Inc v Smith International (North Sea) Ltd [2006] EWCA Civ 185, the Comptroller appeared to present the counter-arguments to Apimed’s appeal. 

It appears from the facts that most honey, including supermarket honey, does have some degree of anti-microbial effect, but if you want to try this at home, make sure that the honey has not been pasteurized, which destroys the effective enzymes - and that there aren't too many ants around.