The influence of the hexylsalicylic acid (2) on the pharmacokinetic of the quinine (1), was studied using rabbits. It could be observed that after i.v. application the mean resistance time (MRT) of 1 was increased by means of ion-pair-formation with 2. But the AUC of 1 was not influenced. After rectal application of the combination 1/2 an acceleration of the 1 absorption could be pointed out. The kinetic parameters of 2 were not increased significantly if 1 was applicated simultaneously.