The pharmaceutical industry and the registration authorities are very interested in the evaluation and comparison of drug release from the pharmaceutical dosage forms. Nowadays several methods are used to help decide if different formulations release their drugs in a similar way, namely statistical methods, mathematical model dependent methods and model independent methods. The statistical methods can be based on nonparametric tests, such as Mann-Whitney test, Kolmogorov-Smirnov Z test or chi-squared test or on parametric tests such as the analysis of variance, univariate (ANOVA) or multivariate (MANOVA), or the t-student test. Drug release from solid dosage forms has been described by kinetic models in which the dissolved amount of drug (Q) is a function of the test time (t), or Q = f(t). Other release parameters, as dissolution time (t x%), assay time (t x min), dissolution efficacy (ED), difference factor (f1), similarity factor (f2) and Rescigno index (x1 and x2), can also be used to characterize the drug dissolution/release profiles.
Dissolution; Dissolution profile; Lyoequivalence; Mathematical models; Dissolution parameters
