[Interactions between 6-chloro-5-cyclohexyl-1-indancarboxylic acid (TAI-284) and biopolymers (author's transl)]

TAI-284, a new non-steroidal acidic analgesic and anti-inflammatory agent was investigated and the interactions with biopolymers were compared with those of indomethacin (IMC) and ibuprofen (IP). TAI-284 inhibited the heat denaturation of bovine serum albumin at pH 5.3, similar to that seen with IMC and weaker than that seen with phenylbutazone. TAI-284 prevented the rat erythrocyte from heat-induced hemolysis and was twice as potent as IMC. TAI-284 produced alterations in platelet function as characterized by loss of secondary aggregation in response to ADP and inhibition of aggregation by collagen. Both these effects were one fifth as potent as those seen with IMC. In rats, platelet aggregation induced by collagen and secondary ADP aggregation was reduced in a dose-dependent manner by a single oral administration of TAI-284. The inhibitory activity was approximately one fourth that of IMC or twice that of IP in the former and in the latter one fifth that of IMC or similar as that of IP. These results suggest that the essential feature of TAI-284 is its potent membrane stabilizing action which is considered to be an necessary mechanism in the action of anti-inflammatory drugs. It is considered that TAI-284 may be less active than IMC in inhibiting prostaglandin biosynthesis in platelets.