Comparison of Chemical Behavior of Original and Generic Docetaxel Formulations as Non-alcoholic Preparations: Discussion about Diluent Solvents for Docetaxel

Although generic anti-tumor agents are in wide clinical use, they have not in all cases been shown to be equivalent to the original agents after preparation. In the present study, original and generic docetaxel formulations were compared with respect to stability when prepared as a non-alcoholic solution for use. When the original formulation was diluted with physiological saline solution to make a non-alcoholic preparation, the concentration decreased with time, whereas no such decrease occurred when a preparation of the generic formulation was made in a similar manner. With both the original and generic formulations, no decrease in docetaxel concentration with time was found after dilution with 5% glucose solution. On the basis of these results, it is concluded that the behaviors of original and generic docetaxel formulations are not equivalent when prepared, but that the original and generic formulations can be taken to be equivalent if they are diluted with 5% glucose solution at preparation.