Comparison of In Vitro Dissolution Profiles of Oxcarbazepine-HP b-CD Tablet Formulations with Marketed Oxcarbazepine Tablets

Abstract

The aims of this study were (1) to compare the in vitro dissolution profiles of oxcarbazepine-HP b-CD tablet formulations with those of marketed oxcarbazepine tablets, (2) to apply statistical models to evaluate each method in terms of easy application and usefulness, and (3) to identify the advantages and disadvantages of each method. The results show that the tablets containing hydroxypropyl b-cyclodextrin (HP b-CD) with sodium carboxymethylcellulose (NaCMC) exhibit faster release (1.93-fold) than marketed oxcarbazepine (OXO) tablets. From Weibull parameters, it was shown that Td is three times higher for OXC-HP b-CD with NaCMC tablets than for marketed oxcarbazepine tablets. The release kinetics of OXC complexed with HP b-CD from different tablets was investigated using several mathematical equations. Model-independent methods including difference factor, f1, and similarity factor, f2; model-dependent methods; and ANOVA-based methods were used for the comparison of in vitro dissolution profiles. The results show that ANOVA-based methods and model-dependent methods are more discriminative than model-independent methods. Modelindependent methods seem to be easier to apply and interpret; only one value is obtained to describe the closeness of the two dissolution profiles. The application and evaluation of model-dependent methods are more complicated; these methods present an acceptable model approach to the true relationship between percent dissolved and time variables, including statistical assumptions that could be checked. Drug release data fit well to the Hixson–Crowell model. The drug release mechanism was a graphic of the cube root of the unreleased fraction of the drug with time. The Weibull model was more useful for comparing the release profiles. Weibull parameters were more sensitive to the differences between the two release kinetic data sets.