Interior Form of Vessel and Dissolution Test

It has been reported that inside bottom curvature varies from one vessel to the next and irregular surfaces can occur, depending on the conventional glass processing techniques. Such non-uniformity of bottom curvature and surface irregularity cause dissolution results to differ significantly.1),2),5)

Dissolution testing has remarkably increased in value and significance over the last 30 or so years. It has been widely employed as an important tool in formulation development, in bioequivalence studies and in quality control. It is well known that the dissolution test involves many variables that can contribute to inaccurate results. Therefore, the current USP, EP and JP specify in detail mechanical parameters of the dissolution tester itself such as a shaft rotation speed, shaft position, wobble, distance of blade to inside bottom of vessel and the like. However, considering the vessel alone, only height and inside diameter are stated as dimensions. In addition, the tolerances of each dimension have been actually quite wide.

An innovative integrated fabrication technique developed by Takao could finally bring a solution to large variation of dissolution results. The most precise and accurate glass vessels were developed by the technology for the first time in the world.