2.9.3.2 Food or Medicines, Being Mere Admixtures

Note: An objection under sec 50(1)(b) should only be raised in exceptional circumstances. In the case of pharmaceutical preparations, an objection of lack of inventive step should be taken in preference to an objection under sec 50(1)(b). Similarly, in the case of food, an objection should be taken on the basis of lack of inventive step rather than under sec 50(1)(b), unless the invention is no more than a simple recipe.

Under sec 50(1)(b), the Commissioner may refuse to accept a patent request and specification relating to a standard patent, or to grant a standard patent, on the ground that the specification claims as an invention:

• a substance which is capable of being used as a food or medicine (whether for human beings or animals and whether for internal or external use) and is a mere mixture of known ingredients; or
• a process producing such a substance by mere admixture.

By "mere mixture of known ingredients" is meant a mixture exhibiting only the aggregate of the known properties of the ingredients. Not only must the ingredients be known, but the property which makes the ingredients useful for the purpose of the invention must also be known.

"Mixtures" may encompass not only powders or granules, either loosely or in compacted form (e.g. a tablet or pill), but also mixtures of liquids or gases and includes suspensions and solutions.

A substance is not excluded from being a mere admixture merely on the basis that the physical form of an ingredient has been changed, e.g. a sweet formed from a mixture of sugar and cellulose which has been turned hard by boiling (see the obiter in Ashe Chemicals Ltd. (Deadman's) Appln. (1972) RPC 613 at page 621).

Examination Practice

The concept of “mere admixture” overlaps with inventive step.  With inventive step available as a ground of objection under the 1990 Act, this is the more appropriate objection and is consistent with international approaches.  Therefore, where there is a reasonable basis for an inventive step objection, this should be taken in preference.  A mere admixture objection should be reserved for cases where there is a combination or collocation of very well known ingredients in a simple recipe (or process of making such by mere admixture), where it can be difficult to obtain documentary evidence to support lack of inventive step, or establish a specific motivation to combine the particular ingredients.

An example of where mere admixture may apply is a simple recipe, such as a pizza dough containing particular herbs in the base. The herbs are used in an established and predictable way to change the taste of the dough, without providing any technical advantage over previously known doughs.

Where an objection under sec 50(1)(b) is disputed by the applicant and the examiner considers it should be maintained, the matter should be referred to a supervising examiner before a further report is issued.