Could this be the substance patented against salmon lice?
Fish Farming Expert's Norwegian sister site, Kyst.no, has tried to find out what lies behind the news that a new remedy against the parasite that will be tested.
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Vestland Pharma reports that it has patented something that could become a new drug against salmon lice, and that they have now brought Coast Seafood and the venture company Sarsia and seafood exporter Coast Seafood on board as owners to finance testing.
We asked the chief executive of Vestland Pharma, Jan Rune Nordhagen, for further details.
"At the moment, we are not disclosing the chemical components of the new drug, but this will be made known at launch."
However, he says that they have conducted a number of 'proof of concept' studies and that these studies on a smaller scale have shown two important things:
"Firstly, we have documented that the drug is very effective against salmon lice. Secondly, the fish in the studies have not shown signs of being harmed by the treatment," says Nordhagen.
What are the plans for further testing?
"It is important for us now to follow the steps required to document the drug according to DMP's (formerly the Norwegian Medicines Agency) guidelines. This involves, among other things, documenting efficacy, safety, and impact on the external environment. Fortunately, we find that we, both internally with investors and owners, and externally, have a good overview and clear plans for this documentation."
He adds that DMP (Direktoratet for medisinske produkter) has been very helpful with guidance in this early phase.
Sell before marketing authorisation
He says they hope to start documentation testing next year.
"We hope to be able to start full-scale field trials already by next autumn. We believe, but cannot guarantee, that we can come under arrangements that allow farmers to use the drug before full marketing authorisation is granted. If this is not possible, we estimate that it will take about a year after full-scale field trials for the product to be ready for the market," he says.
Could it be potassium?
As mentioned above, Nordhagen does not want to say anything about the active ingredient in the new preparation, nor say anything on direct questions about whether this is about potassium.
The reason we speculate that ions of the alkali metal are involved is that we find the following patent associated with Vestland Pharma:
"Preparation containing sea water added a potassium compound"
Vestland Pharma is listed as the "Current Assignee".
The inventor mentioned is veterinarian Inge Arne Kandal, who works as an office manager at salmon farmer Nordfjord Laks, which operates two farming concessions in the municipalities of Stad and Gloppen, at its sites in Hyefjorden and Nordfjorden.
Kandal has also had a part-time position at Vestland Pharma.
The patent was originally applied for by Leiv Slagstad, Nordfjord Laks AS and Lutra AS.
In the patent application, the invention is described as a preparation containing seawater with an added potassium compound.
"The preparation is intended for use as a bath treatment and contains seawater with an added potassium compound, so that the amount of potassium ions in the preparation is increased compared to the amount of potassium ions naturally found in the seawater," it states.
The inventors have discovered that potassium ions dissolved in seawater in specific doses have a good effect against salmon lice, while the therapeutic margin for the fish is satisfactory.
Potassium ions are naturally found in seawater at a concentration of about 380 mg/l in water with a salinity of 3.5%. By adding potassium compounds such as potassium chloride, the potassium concentration can be increased to desired levels, they write.
The potassium compound can be a potassium salt such as potassium chloride, potassium bromide, potassium iodide, or potassium nitrate. The amount of potassium ions added can be between 0.78 g/l and 1.21 g/l of seawater, which corresponds to an addition of 1.5-2.3 g of potassium chloride per litre of seawater.
Conducted tests
The patent application describes some tests that have been conducted.
Example 1:
The treatment solution consisted of seawater with an addition of 1.7 g KCl (potassium chloride) per litre of seawater. This corresponds to an addition of 0.89 g potassium and 0.81 g chlorine per litre of seawater. The salinity was thus increased to 36.2 parts per thousand. Ten salmon (Salmo salar) weighing 254-340 g (average 294 g) were infected with a total of 195 salmon lice, or an average of 19 lice per fish.
- The experiment lasted for 5 hours.
- Salmon lice that fell off the fish were collected every 15 minutes.
- After 300 minutes, there were only 58 lice left on the fish, and an additional 7 lice were found in the water.
This shows that the solution had a significant effect on the lice's ability to stay attached to the fish.
Example 2:
A similar solution was used, but with 1.8 g KCl per litre of seawater, corresponding to 0.94 g potassium and 0.86 g chlorine per litre. Fourteen salmon with an average weight of 239 g were infected with 117 adult male and female lice.
- The experiment lasted 5 hours.
- The results showed a similarly significant reduction in the lice's ability to stay on the fish.
Example 3:
In this experiment, a solution with 2.0 g KCl per litre of seawater was used, corresponding to 1.05 g potassium and 0.95 g chlorine per litre. Fourteen salmon with an average weight of 230 g were infected with 137 adult lice.
- The results showed that 50% of the salmon lice fell off after about 120 minutes.
- The higher concentration gave an even stronger effect.
The patent applicants write that examples 2 and 3 show that the salmon lice do not fall off the fish until after about one hour of exposure.
"It is assumed that elevated levels of potassium in the seawater have a paralysing, but not lethal, effect on the salmon lice. The time for exposure until 50% of the salmon lice had fallen off was 172 minutes, 171 minutes, and 120 minutes in examples 1-3, respectively.
"When using known pharmaceutical agents, including hydrogen peroxide, in bath treatment of salmon infected with salmon lice, a reduction of 90% of the adult salmon lice is considered a good and satisfactory treatment result," they point out.
But whether this is the basis for the substance Vestland Pharma is trying to get approved remains to be seen.
