Effect of tranilast oily gel on carrageenin-induced granulation in rats

Tranilast (TL) oily gels consisting of hydrogenated soybean phospholipid and fatty-acid ester were prepared, and the inhibitory effect of the gels on the growth of granulation tissue were evaluated in a carrageenin-induced rat granulation model. By the application of 0.1 and 0.2% TL oily gel, the weight of granulation tissue was significantly reduced to 64 and 55%, respectively, of control value. Furthermore, these gels reduced their respective hydroxyproline content to 64 and 51% of the control. On the other hand, the inhibitory effect of 10% TL ointments, which are clinically used for the treatment of keloids and hypertrophic scars as hospital preparations, was much lower than that of the oily gels. In addition, the application of 0.1 and 0.2% oily gel led to high concentration (0.1% gel, 168+/-18 microg/g; 0.2% gel, 221+/-16 microg/g) of TL in the dermis as compared with the 10% TL ointments. These results suggest that TL oily gels may be a useful topical formulation for the treatment of keloids and hypertrophic scars.