T 2027/13 - "Consisting essentially of" unclear

Key points

• A claim for a pharmaceutical composition comprising an active ingredient and a release controlling agent "consisting essentially of" ethyl cellulose and optionally pharmaceutically acceptable excipients, was held to be unclear by the  board. The objection was resolved by replacement of the wording "consisting essentially of" with "being".

EPO T 2027/13 - link

Reasons for the Decision

Main request - clarity

1. Claim 1 of the main request concerns a controlled release pharmaceutical composition "comprising" a specific active ingredient (pregabalin or salts thereof), a hydrophobic release controlling agent "consisting essentially of" ethyl cellulose and optionally pharmaceutically acceptable excipients.

1.1 The appellant has argued that the expression "consisting essentially of" was considered as clear in the case law and in the present case necessarily meant that the composition did not contain any additional hydrophobic release controlling agent, but could contain other excipients or impurities which did not alter the controlled release properties of the composition.

In T 1170/07 (supra), where claim 1 of the main request included a dosage form which consisted essentially of an active ingredient, the board concluded that under the specific circumstances of the case "consisting essentially of" excluded further active agents useful in the treatment of the specific disease mentioned in the claim, but allowed the presence of additional compounds forming the carrier of the agent (see point 3.1 in the reasons). By virtue of that interpretation no problem of clarity arose.

1.3 In T 1730/09 (supra), where claim 1 of auxiliary request 8 concerned a viscoelastic fluid consisting essentially of three ingredients, reference was made to previous decisions, wherein it was decided that the term "consisting essentially of" was clear and allowed the presence of other components in a claimed composition in addition to the components mandatory in the claim, provided that the essential characteristics of the claimed composition were not materially affected by their presence (point 1.2.3 in the reasons, first paragraph). The board agreed with these previous decisions and concluded that in the present case the wording used allowed that the composition consisted of the mandatory components listed in the claim and could contain additionally only other components which did not materially affect the essential characteristics of the composition (in the specific case the viscoelastic characteristics), e.g. minor amounts of impurities (point 1.2.3 in the reasons, second paragraph).

1.4 In all cited cases the expression "consisting essentially of" refers to the whole composition present in the claim. This is the case also in T 1170/07, where, even if the unit dosage includes a single ingredient, it is the whole dosage form which consists essentially of that ingredient (and not the ingredient which consists essentially of one component).

1.5 Contrary to that, in the present case the composition is defined by an open formulation (in view of the word "comprising"), which already implies the presence not only of the optional excipients, but also of any additional pharmaceutically acceptable component (including impurities) and even on further release controlling agents, and the expression "consisting essentially of" refers to a single ingredient of the composition.

1.6 As the usual reading of the expression does not make sense in the present case (the presence of any additional ingredient is already encompassed by the open formulation), the skilled person reading the claim is at a loss about the possible limitation introduced by the expression. In particular, he could not consider it as implying that no additional hydrophobic release controlling agent is present, which is not the case in view of the open formulation, nor could he see the limitation as necessary to allow the presence of excipients or impurities, which are already included independently of the presence of the expression.

1.7 As it is not clear what limitation is introduced by the expression "consisting essentially of" with respect to the hydrophobic release controlling agent in claim 1 of the main request, the claim does not meet the requirements of Article 84 EPC.

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Auxiliary request 5 - clarity and amendments

3. Claim 1 of auxiliary request 5 corresponds to claim 1 of auxiliary request 2 (which in turn corresponds to claim 1 of the main request with cosmetic amendments) with the replacement of the wording "consisting essentially of" with "being".

3.1 By means of this amendment the objection under Article 84 EPC valid for the previous requests is rendered moot. The Board has no reason to raise further objections under Article 84 EPC.