ON APPEAL FROM THE PATENT OFFICE
Strand, London, WC2A 2LL
B e f o r e :
| VERICORE LIMITED
|- and -
|(1) VETREPHARM LIMITED
Mr Richard Hacon (instructed by Bristows for the Respondent)
Hearing dates: 21 - 22 July, 2003
Crown Copyright ©
Mr Justice Laddie:
"Accordingly, the invention provides the use of a pyrethroid pesticide, preferably cypermethrin or alphacypermethrin, for the manufacture of a composition for treatment of sea lice infestation in salmon or other sea fish in a seawater environment."
"1. Use of a pyrethroid pesticide for the manufacture of a composition for the treatment of sea lice infestation in seawater fish in a seawater environment.
"6. Use of a pyrethroid pesticide in water for the manufacture of a treatment suspension for salmon suffering from sea lice infestation.
"9. A composition when used for controlling sea lice infestation in salmon which comprises a pyrethroid pesticide suspended in water."
"Certainly, it is particularly surprising that alphacypermethrin is highly effective when administered orally. Good results at dosage rates equivalent to 0.005 mg/litre in water have been found whereas the dosage rate for dichlorvos [a prior art pesticide] to give equivalent results is of the order of 1 mg/litre.
The active ingredients used according to the present invention are preferable administered to the salmon or other fish in their feed but they could be added as a water or bath treatment to the fish.
The active ingredient can be used in suspension or emulsified concentrate form or as a solid formulation (e.g. powder or granules) of a particle size typically in the range 10 to 103 microns. The range of suspension concentrate formulations is suitably 10 250 g active ingredient per litre, and powder or granular formulations typically being 1.0 to 2.5% w/w pre-mixes added to finished feed.
Accordingly the invention also extends to the use of a pyrethroid pesticide in water for the manufacture of a treatment suspension for salmon suffering from sea lice infestation, and to a food composition suitable for salmon, characterised in the in (sic) addition to food ingredients it contains (sic) a pyrethroid pesticide.
Suitably the active ingredient is administered orally, for example in feed to achieve a dose range of , and is added to baths at a range of between 0.001 and 0.5 ppm by weight of pyrethroid pesticide to water (i.e. between 0.001 and 0.5mg of active ingredient of pesticide in 1 kg of water)." (patent pages 2 3)
The proposed amended claims
"Use of a pyrethroid pesticide for the manufacture of a composition for the treatment of sea lice infestation in seawater fish in a seawater environment, wherein the composition is an emulsified concentrate".
"The teaching of Prior Art D1, D2, and D9
14. From the above, it is my clear opinion that the use of an emulsion for testing a compound of low solubility in water was a well known and obvious approach to take. If the solubility is high, a formulation as a solution is normally preferred. As synthetic pyrethroids are very slightly soluble in water, a formulation that resulted in a solution of the active ingredient at the required concentration in the bath would be unlikely to be an option, and an emulsion would therefore be an obvious choice. This approach to formulation was standard practice and would have been well known to fish health specialists, who would have been familiar with the use of dichlorvos, and was therefore a part of the common general knowledge of fish health specialists."
"10. Furthermore, as Professor Horsberg states in paragraph 14 of his Report, the synthetic pyrethroids are only very slightly soluble in water and therefore an emulsion would be an obvious choice of formulation. I would agree with this, absent the teaching of D2 and D9. I would add that this also applies to pyrethrum and so the skilled person would have believed that the Austevoll team would have concentrated their work on emulsions until they had exhausted that line of experimentation."
"PYRETHRUM, a neuroactive mixture of pyretrins, is an effective pesticide. Introductory tests at the Marine Aquaculture Station Austevoll have shown that this substance can be toxic to fish if emulsified (finely distributed in water). However, this problem has been averted and the fish can now be deloused without the risk of dying because the salmon louse has a lipid layer in its outer shell, while the salmon's slimy outer layer is water soluble. By allowing the salmon to hop through a layer of oil containing the fat soluble pyrethrum, we found that we could get pyrethrum into the salmon louse in effective concentrations, while leaving the fish unaffected.
In the following, we present the results of one of several tests carried out at the Marine Aquaculture Station Austevoll in the autumn of 1989, which in our opinion demonstrates pyrethrum's potential. The treatment method described here is probably not optimal. A number of optimisation tests will hopefully be carried out at the Marine Aquaculture Station Austevoll in 1990."