Abstract: 4-Imidazoline derivatives represented by the formula (I) and/or formula (II): ##STR1## wherein R.sup.1 represents C.sub.1 -C.sub.8 alkyl, C.sub.3 -C.sub.8 alkenyl, C.sub.3 -C.sub.8 alkynyl, C.sub.3 -C.sub.8 cycloalkyl, or optionally substituted aralkyl; R.sup.2 and R.sup.3 independently represent hydrogen, C.sub.3 -C.sub.20 alkyl, C.sub.3 -C.sub.20 alkenyl, C.sub.3 -C.sub.20 alkynyl, C.sub.3 -C.sub.20 alkoxy, C.sub.3 -C.sub.20 alkenyloxy, C.sub.3 -C.sub.20 alkynyloxy, C.sub.3 -C.sub.8 cyloalkyl, C.sub.1 -C.sub.10 alkylthio, or optionally substituted aralkyl or aralkyloxy; R.sup.4 represents C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.8 cycloalkyl, or optionally substituted aralkyl; provided that R.sup.2 and R.sup.3 cannot be hydrogen at the same time, and pharmaceutically acceptable salts thereof. A pharmaceutical formulation containing the compound is also provided.

Abstract: A lipid-peroxide formation inhibitor useful as a preventive medicine and/or therapeutic medicine against various ischemic diseases and accompanying diseases such as various brain diseases, heart diseases and peripheral circulatory diseases and novel pyrazolone derivatives having such inhibitory activity and their pharmaceutically acceptable salts.

Abstract: A lipid-peroxide formation inhibitor useful as a preventive medicine and/or therapeutic medicine against various ischemic diseases and accompanying diseases such as various brain diseases, heart diseases and peripheral circulatory diseases and novel pyrazolone derivatives having such inhibitory activity and their pharmaceutically acceptable salts.

Abstract: A lipid-peroxide formation inhibitor useful as a preventive medicine and/or therapeutic medicine against various ischemic diseases and accompanying diseases such as various brain diseases, heart diseases and peripheral circulatory diseases and novel pyrazolone derivatives having such inhibitory activity and their pharmaceutically acceptable salts.

Abstract: A prophylactic and therapeutic agent for circulatory disorders, comprising a pyrazolone derivative of the formula: ##STR1## wherein R.sub.1 represents a hydrogen atom, an aryl group, an alkyl group having 1 to 5 carbon atoms or an alkoxycarbonylalkyl group having a total carbon number of 3 to 6; R.sub.2 represents a hydrogen atom, an aryloxy group, an arylmercapto group, an alkyl group having 1 to 5 carbon atoms or hydroxyalkyl group having 1 to 3 carbon atoms; or R.sub.1 and R.sub.2 taken together represent an alkylene group having 3 to 5 carbon atoms; R.sub.

Abstract: Certain new 1-alkylamino-4-phenylphthalazine derivatives, 1-neopentylamino-4-phenylphthalazine and 1-(1-ethylpropylamino)-4-phenylphthalazine, having prominent activity to ameliorate circulatory disorders and prepared from the corresponding phthalazinones.

Abstract: Novel substituted phenylacetic acid derivatives having the formula: ##STR1## wherein R.sub.1 represents a hydrogen atom or lower alkyl radical and R.sub.3 represents an alkenyl or alkynyl radical having 3 - 4 carbon atoms with excellent anti-inflammatory and analgesic activities.

Abstract: A prophylactic and therapeutic agent for circulatory disorders, comprising a pyrazolone derivative of the formula: ##STR1## wherein R.sub.1 represents a hydrogen atom, an aryl group, an alkyl group having 1 to 5 carbon atoms or an alkoxycarbonylalkyl group having a total carbon number of 3 to 6; R.sub.2 represents a hydrogen atom, an aryloxy group, an arylmercapto group, an alkyl group having 1 to 5 carbon atoms or hydroxyalkyl group having 1 to 3 carbon atoms or R.sub.1 and R.sub.2 taken together represent an alkylene group having 3 to 5 carbon atoms; R.sub.