PJ Online | News: Losec formulation patent overturned

Home > PJ > News / Daily News | Search

The Pharmaceutical Journal
Vol 268 No 7189 p349-354
16 March 2002

Losec formulation patent overturned

The High Court in London has ruled that AstraZeneca's formulation patent for Losec (omeprazole) is invalid. Mr Justice Laddie ruled on 8 March that the principal claim in the patent was "obvious".

The case was brought by two companies, Cairnstones and Generics UK. The formulation patent describes how omeprazole is formulated as a central alkaline core material and a separating inert layer between it and the outer enteric coating. Without the inert layer, the active ingredient would be degraded by contact with the acidic enteric coat. The claimants argue that excipients used in such a formulation are obvious on the basis of common general knowledge.

Mr Justice Laddie said that common sense dictates that the possibility of chemical interaction between a new drug and excipients would be recognised by a formulator. He added that a skilled worker would almost immediately have found an incompatibility problem between omeprazole and the enteric coating. An obvious solution to this would have been to use a separating layer between the two that would dissolve or disintegrate in the intestine to avoid bioavailability problems.

AstraZeneca has been given permission to appeal against the decision. Dr Martin Nicklasson, executive vice-president, gastrointestinal franchise, said: "We are disappointed by this judgement and remain confident that the decision can be overturned in our favour on appeal."

However, a spokesman for Generics UK said: "We are very pleased with this outcome and also surprised that AstraZeneca appears so confident about the appeal. The implications of this patent being found invalid include paving a way for generic competition."

Worldwide, there are 71 ongoing cases considering patents for omeprazole, according to a spokesman for AstraZeneca. This includes a case in the Unites States considering the drug's formulation patent (PJ, 1 December 2001, p775) which has yet to reach a conclusion.

The availability of generic competition is a prime concern for three primary care organisations in England. Fareham and Gosport Primary Care Group, Portsmouth City PCG and East Hampshire Primary Care Trust have written to all pharmaceutical companies in the United Kingdom to point out that tactics used to delay or prevent the launch of generic drugs might damage their future working relationship with them.