A dried product of an extract from inflammatory rabbit skin inoculated with vaccinia virus having an inhibitory activity for the production of a kallikrein-like substance is produced by admixing the extract with a saccharide, sugar alcohol or ascorbic acid before reaching dryness, and then drying the admixture to a solid form such as granules. The dried product may be employed to produce a solid preparation for oral administration, such as tablets, having an inhibitory activity for the production of a kallikrein-like substance.