Dissolution testing is an essential process in the development and manufacture of oral solid pharmaceutical products. There are two certificates relevant to dissolution testing - COC and COA. Although both are used to ensure that certain standards are met, there are important differences between COC and COA when it comes to dissolution.
The guidelines for dissolution testing are set by the USP, EP and/or JP. This means that all dissolution testers and their accessories must meet the specifications defined in the monograph. These specifications are generally physical and can be measured with the appropriate tools. Thus all baskets, paddles, basket shafts, vessels and any other part of the system should be both defined and measurable within the specified tolerances.
All dissolution accessories should conform to these specifications and the certification that they do is known as a COC or Certificate of Conformance. The COC generally defines the tolerances to which the accessories are manufactured and these should be within the tolerances defined by the USP.
All QLA dissolution accessories are supplied with a COC.
A COA is much more stringent than a COC and records the actual physical measurements of each individual accessory or part. This means that each part is individually measured and recorded by the manufacturer. The COA exceeds the COC in that it is possible to know the exact measurements and therefore record them for individual test positions.
As a COA is quite time consuming and involved, there is usually an additional charge for it.
In addition to the use of certified and traceable measuring tools, more sophisticated equipment is used to ensure that all parts meet very tight manufacturing tolerances. Products such as optical comparators are used to compare manufactured parts with perfect originals, and normal tolerances are much tighter than defined in the USP to ensure consistency from part to part. This is important to ensure reproducible results between each inspection position.