The claim at issue mentioned a chemical composition comprising, besides some active substances, a "solvent". In all the embodiments, the solvent was such that it contained at least one acidic group and the technical teaching indicated that the acidic group has a function while giving no inducation how other suitable solvents could be found.
The Bundespatentgericht ruled that the claim was too broad because the invention was generalized beyond the contribution of the invention to the prior art. The disclosure is not sufficient in terms of practicability if the skilled person has to apply the priciple of trial and error for finding suitable chemicals out of a unmanageable quanity of possible candidates. For the full text (in German), click here.