A method of deactivating and on-press developing an exposed lithographic printing plate is disclosed. A compound represented by the general formula :wherein R represents a pyridyl group substituted with 1 to 3 group independently selected from Substituent Group A, and Substituent Group A represents a halogen atom, a C1-C6 alkyl group and a C1-C6 alkoxy group or a pharmacologically acceptable ester thereof, or a pharmacologically acceptable salt of the compound or ester. A cutting tool is located at the distal end of the tube, and is positioned adjacent to the cutting window.