Glaxo is suing Geneva, the US subsidiary of Ciba Geigy, the Swiss group, and two other companies, Interchem Trading, a US chemical distributor, and Union Quimico Farmaceutica, a Spanish chemical manufacturer. It claims they have infringed its patents on the 'form 2' version of ranitidine hydrochloride, Zantac's active ingredient, and the process used to make it.
In March, Geneva said it was asking the US Food and Drugs Administration for permission to market an early version of the drug known as 'form 1' when the patent expires at the end of 1995. Glaxo has only ever marketed the later 'form 2' version, the patent on which runs until 2002.
Glaxo argues it is impossible to manufacture form 1 without also producing form 2, and so infringing its patent on the later version.
The legal action means that, even if the FDA approves Geneva's application, it is unlikely to be allowed to start marketing the drug until September 1996 at the earliest.Reuse content