Similarity Testing

Similarity testing has been introduced with the chapters on biological assays in the US Pharmacopeia <1032>, <1033>, <1034> it is the approach to prove the validity of your bioassay. In similarity testing, you compare regression parameters, differences of parameters or ratios or parameters along with their confidence intervals to equivalence margins. If the confidence interval falls completely into the range of the equivalence margins, the test is passed.

The challenge of this type of testing is the development of suitable equivalence margins. The Equivalence Margin Development document type of PLA 3.0 allows you to calculate candidate equivalence margins from historic assay data.

All regression parameters can be tested as 

• absolute parameter tests
• difference of parameter tests
• ratios of parameter tests
• scaled ratio of parameter tests

In addition

• tests of asymptote ranges 
• tests of asymptote ratio
• scaled ratio of asymptotes

are available as well.
_{Please note: not all tests are available with every regression model.}