A dynamic seal advantageously utilizes a groove on the active side or surface of the seal to capture a leaked lubricant and hydrodynamically pump the lubricant back into the lubricated side of the seal. More specifically the present invention relates to crystalline Arginine -2-Ethoxy-3-{4-2-ethoxyphenyl}propanoate, preferably -Arginine -2-Ethoxy-3-{4-2-ethoxyphenyl}propanoate, its preparation and its use as therapeutic agent. The bogey beam is connected to the frame by a pivot assembly defining a transverse pivot axis about which the bogey beam can oscillate.