Abstract
Biopharmaceutical investigations were made to determine the reason for differences in therapeutic responses to two types of carbutamide tablets with the same carbutamide content. A two-way cross-over study in five healthy adult men on the serum concentration of carbutamide, measured by HPLC, showed differences between the tablets in terms of the mean serum concentration at 2 h (31.48 and 42.89 μg/ml, respectively) and Cmax (37.30 and 48.83 μg/ml, respectively). These findings were reflected in differences in therapeutic effects. Marked differences were also found between the tablets in in vitro tests, e.g., in disintegration time, hardness and dissolution rate. The findings were consistent with clinical findings only when a pre-incubation technique was employed in the in vitro dissolution test.
