If a patent is so amended that a claim to a product (a physical entity) is replaced by a claim to the use of this product, the degree of protection is not extended, provided that the use claim in reality defines the use of a particular physical entity to achieve an effect and does not define such a use to produce a product (see G 2/88).
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/h_v_7_1.htm
Date retrieved: 17 May 2021