A discriminatory test reflects that it can differentiate a bad batch/product from a good one. The question is, how should one define bad vs. good? In general a good product, in the context of dissolution testing, is a product that should be capable of releasing a drug from the product in the GI tract in an expected and reproducible manner. It is important to note that a drug release, or dissolution test is linked to product behavior in the GI tract. On the other hand, it is a well-known fact that currently suggested dissolution methods/testers have no link to the product behavior in the GI tract (link). In fact, it is almost impossible to obtain reliable and physiologically relevant dissolution results using currently suggested apparatuses, particularly paddle/basket apparatuses, because of the flaws of the testers (link). Therefore, it is almost impossible to have discriminatory dissolution methods to differentiate a bad product from a good product by extension.
The irrelevancy of current practices of developing discriminatory tests, methods or testers may also be explained in another way with the following analogy. For example, one may ask if anyone has seen a discriminatory thermometer, laboratory balance, pH meter, spectrophotometer, chromatograph etc. The answer is, not really; because all one does, by using a tester/method, is to measure the parameter’s value. The test/method is used only to determine value/result, and the scientist/analyst uses this value for the interpretation of the characteristics of the product. For example, one never says, requires or develops a discriminatory thermometer when one monitors the temperature. One uses the thermometer to measure the value (temperature) of the corresponding parameter (body temperature). The thermometer never tells if a person has a fever or not. It only tells the temperature, but a physician interprets it as a fever or any other deviation. So, why does one have discriminatory dissolution methods or testers? It is simply to market the made-up science and flawed testers. Developing a discriminatory test/method, as practiced or required, has no meaning and serves no useful purpose. One requires a dissolution tester or method to measure the dissolution characteristics of a product reflecting it’s in vivo dissolution characteristics. Once one has such a method, it automatically becomes a discriminatory test. One does not require any extra effort or steps to make it a discriminatory test. The dissolution results thus obtained using such a method/tester would reflect dissolution characteristics of a product, and then the analyst/formulator is to decide whether the product is of acceptable quality/characteristics or not. Read the rest of this entry �