On 18 October 2007, the England and Wales Court of Appeal (the Court) handed down a decision in Novartis (AG) v IVAX Pharmaceuticals UK Limited (IVAX) that concerned an appeal lodged by Novartis against a decision of Pumfrey J declaring IVAX’s “Equoral” product as not infringing Novartis’ UK patent no. 2,222,770 (the patent). A cross-appeal was advanced by IVAX on the basis that if the patent did cover Equoral, it would be invalid. This cross-appeal was not heard as the Court dismissed the appeal after hearing Novartis’s argument in relation to infringement.

The patent is for cyclosporin galenic formulations in the form of an oil-in-water micro-emulsion pre-concentrate. The relevant invention allows the preparation of solid, semi-solid and liquid compositions containing sufficiently high concentrations of cyclosporin to permit oral administration and improved efficacy.

The Court highlighted that a key point was the definition given to the formulation. The expression “oil-in-water microemulsion pre-concentrate” means a system that is able, on contact with water, to provide an oil-in-water micro-emulsion. Moreover, micro-emulsions meant micro-emulsions comprising a dispersed particular phase, consisting of droplets or particles having a size of less than 2,000 Ångstrom (Å).

IVAX’s product, Equoral, is a formulation containing cyclosporine, available in the United Kingdom in the form of an oral solution and gelatine capsules. The controversy before Pumfrey J, in the first instance, was in relation to whether, and if so, how much, of Equoral consisted of a micro-emulsion. He found that, by taking 2,000Å as the maximum size for an emulsion to be considered as micro, the vast majority of particles by number falls below this limit.

However, importantly, less than 14 per cent of the active ingredient was present in the particles of a size greater than 2,000Å. More than 86 per cent of the active ingredient was present in particles of less than 2,000Å.

Novartis’ main argument was based on the fact that the amount of 14 per cent cannot be considered trivial and it is irrelevant that larger particles are present as, if the larger particles were removed one would still be left with a micro-emulsion.

The Court rejected this argument in light of the fundamental teaching of the patent. That is, to avoid the problems of the prior art by carrying the cyclosporin in micro-emulsion sized particles that, over time, do not turn into emulsion-sized particles. That said, it was inconceivable, in the Court’s view, that the patentee would have also covered products in which the active ingredient is carried by emulsion-sized particle. As a result, Equoral seemed to be exactly what Novartis sought to avoid.

The case was therefore decided by: (i) considering how a skilled person would have understood the language of the patentee; and (ii) deeming the low percentage in Equoral of active ingredient contained in micro-emulsion-sized particles as being irrelevant to the fundamental teaching of the patent, which shows how micro-emulsion sized particles can carry the active ingredient to improve its efficacy.