Abstract: The present invention relates to an agent for the prevention or treatment of diseases associated with excessive proliferation of retinal pigment epithelial cells such as proliferative vitreoretinopathy comprising as the active ingredient N-(3,4-dimethoxycinnamoyl)anthranilic acid represented by the formula: or a pharmaceutically acceptable salt thereof, which has an inhibitory activity on proliferation of retinal pigment epithelial cells.

Abstract: 1-(2-benzimidazolyl)-1,5-diazacyclooctane compounds represented by the formula: ##STR1## wherein X represents a hydrogen atom or a halogen atom; Y represents a covalent bond, a straight- or branched-chain alkylene group having 1 to 6 carbon atoms, or a straight- or branched-chain alkenylene group having 2 to 6 carbon atoms; R represents a hydrogen atom, or a straight- or branched-chain alkyl group having 1 to 6 carbon atoms; and pharmaceutically acceptable salts thereof. The compounds represented above are novel potent and long-lasting histamine HI-receptor antagonist with less-topical irritation, and can be topically administered by inhalation for the treatment of bronchial asthma.