Effects of humidity and temperature on in vitro dissolution of carbamazepine tablets

The rate and extent of dissolution of various approved marketed carbamazepine (CBZ) tablets exposed to 33, 52, 75, and 97% relative humidities at both room temperature and 40 °C, and saturated water vapor at room temperature were compared to fresh unstressed tablets. The dissolution data indicate that exposure of CBZ tabiets to high humidity and temperature can have a profound effect on tablet disintegration and dissolution. The dissolution rates of some batches of CBZ products exposed to 97% humidity at 40 °C or saturated water vapor at room temperature were drastically reduced in only 6–7 days.