While accepted practice in the pharmaceutical industry has been to calibrate dissolution testers using a combination of mechanical checks and performance verification tablets, there is concern about the wide acceptance ranges and variability these generate. As a result the move is towards enhanced mechanical calibration as an alternative, or at least as a precursor, to chemical calibration. In January 2010 the FDA issued guidance on “The use of Mechanical Calibration of Dissolution Apparatus 1 and 2 – Current Good Manufacturing Practice (CGMP)”.

Enhanced mechanical calibration requires strict control of the dimensions of, and the spatial relationships between, critical elements of the dissolution tester. Copley Scientific has identified these critical elements to be the dissolution vessel and lid, and the stirring element. Controlling these, while also maintaining stirring speed and media composition and temperature within tight limits, minimises any instrument contribution to test method variability.

It has long been recognised that dissolution vessel dimensions and irregularities are a major factor in results variability. Using vacuum forming techniques, Copley Scientific has produced a vessel with superior dimensions and which has provided a platform for the development of a new lid and stirring element. This production method guarantees an internal diameter tolerance and blemish-free spherical radius of +/- 0.13 mm (compared with the traditional unit’s +/- 2 mm). Friction-free bearings in the lid and a precision-ground shaft for the stirring element have enabled a 50% reduction in tolerances relating to wobble, verticality and centering. The Dissolution Tester DIS-EMC betters the dimensional tolerances specified by the FDA by a factor of 2.

The ‘audit-proof’ Copley Scientific Dissolution Tester DIS-EMC provides the highest standards in dissolution testing equipment. In addition, existing users of Copley DIS 6000 and DIS 8000 Dissolution Testers can upgrade to the new DIS-EMC Tester specification by exchanging their standard Test Station for the new EMC Test Station