Before one uses a tester/method, it is mandatory, in particular in a GMP environment, that the validity of its use be established i.e. does the tester/method measure the expected characteristics of the product? In the case of a dissolution tester/method, one expects that it should measure the drug dissolution/release characteristics of a product and should be able to differentiate between products having different dissolution/release characteristics. In addition, a tester/method should not just measure and/or show such differences but these measurements and differences have to be relevant and useful. Please click here for complete article