Drug delivery systems have been developed based on the formation of diketopiperazine carboxylate salts and microparticles containing the same. The systems may further comprise a bioactive agent. Related methods for making and using the biologically active agent delivery compositions are also provided. In certain embodiments, the pharmaceutically acceptable salts described can be formed by removal of solvent by methods including distillation, evaporation, spray drying or lyophilization.

Drug delivery systems have been developed based on the formation of diketopiperazine carboxylate salts and microparticles containing the same. The systems may further comprise a bioactive agent. Related methods for making and using the biologically active agent delivery compositions are also provided. In certain embodiments, the pharmaceutically acceptable salts described can be formed by removal of solvent by methods including distillation, evaporation, spray drying or lyophilization.

The present invention provides a compound of Formula (I) or a salt thereof; ##STR00001##
and therapeutic uses of these compounds. The present invention further provides pharmaceutical compositions comprising these compounds, and compositions comprising these compounds with a therapeutic co-agent.

Drug delivery systems have been developed based on the formation of diketopiperazine carboxylate salts and microparticles containing the same. The systems may further comprise a bioactive agent. Related methods for making and using the biologically active agent delivery compositions are also provided. In certain embodiments, the pharmaceutically acceptable salts described can be formed by removal of solvent by methods including distillation, evaporation, spray drying or lyophilization.

Drug delivery systems have been developed based on the formation of diketopiperazine carboxylate salts and microparticles containing the same. The systems may further comprise a bioactive agent. Related methods for making and using the biologically active agent delivery compositions are also provided. In certain embodiments, the pharmaceutically acceptable salts described can be formed by removal of solvent by methods including distillation, evaporation, spray drying or lyophilization.

[Object] The main object of the present invention is to provide a fibrosis inhibitor. [Solving Means] The present invention relates to a fibrosis inhibitor containing the heterocyclic derivative represented by the following general formula (1) or a pharmaceutically acceptable salt thereof as an active ingredient; ##STR00001##
In the formula (1), R.sup.1 and R.sup.2 are the same or different and each represents an optionally substituted aryl; R.sup.3 and R.sup.4 are the same or different and each represents hydrogen atom or alkyl; R.sup.5 represents hydrogen atom, alkyl or halogen atom; Y represents N or N.fwdarw.O; A represents NR.sup.6, and R.sup.6 represents hydrogen atom, alkyl, etc.; D represents alkylene or alkenylene which is optionally substituted with hydroxy; E represents phenylene or a single bond; G represents O, S, etc.; and Q represents carboxy, alkoxycarbonyl, etc.