Further, the present invention relates to the novel use as elastase inhibitors containing derivatives of p-guanidinobenzoic acid, as active ingredient, represented by the general formula: ##STR15## [wherein Y represents an oxygen atom or a sulfur atom and i) when Y is an oxygen atom, R2 represents (i) a hydrogen atom, (ii) an alkyl group of one to four carbon atoms, (iii) an alkoxy group of one to