The stability study of the lapatinib formulations prepared with 4 different triblock copolymers used in this study (at constant polymer feed of 10 g/L and increasing drug feed from 2 to 10 g/L). The formulations were stored at ambient conditions with initial precipitate. The quantification was done by HPLC at day 0, 1, 5 and 30. All the formulations were centrifuged at 10.000 rpm prior to collecting the samples.