Abstract
As a contrast agent for echocardiography, an injectable suspension containing air-filled microspheres (as active ingredient) produced by sonication of 5%human serum albumin is under development. Thisagent is echogenic and produces backscattering at the interfaces of the air and blood, organs or tissues in the body during ultrasonic examination, providing a range of information including the visualization of blood flow.
Since this contrast agent contains air inside the albumin-shelled microspheres, it has been anticipated that physical shock or vibration might affect the quality of this agent. We have conducted a shipping study to investigate the influence of transportation from the manufacturer to the hospital and the storage conditions on the physicochemical properties of this agent. Despite the severe transport conditions including substantial and frequent physical shocks, changes in temperature, a high position drops, and vibration, no significant changes were found in the microspheres' physicochemical properties, demonstrating their relatively high stability. When product exceeding the shelf life by one month was subjected to the shipping study, however, precipitates were clearly observed on the bottom of the vials after transportation.
