“The mean IC50, IC90 and IC99 values for pyronaridine were 12.7, 201.4 and 3084.2 nM, those for pyronaridine + retinol "low" 1.… nM, and those for pyronaridine + retinol "high" 0.9, 8.2 and 47.8 nM. There was significant evidence of strong synergism between pyronaridine … retinol ….”