Interaction studies between drugs and a purified natural clinoptilolite

Taking into account the biological properties of the purified natural clinoptilolite, NZ, some studies were conducted to evaluate the physicochemical interaction between this zeolite and two drugs, metronidazole and sulfamethoxazole, which cause considerable gastric side effects. Two modified forms of NZ were also considered. We have studied the drug solutions before and after the contact with the zeolitic materials in a wide range of pH values by UV spectroscopy. The structure of the two drugs remains unaltered after interaction with the zeolitic products. It is demonstrated that metronidazole adsorption by the different materials is small in acidic pH, and that the zeolitic materials studied do not adsorb sulfamethoxazole at the considered pH values. The overall study suggests the possibility of parallel administration of these products. These results are coherent with a complementary investigation by transmission IR spectroscopy about the possible incorporation of drug on NZ and its modified forms. (C) 2003 Elsevier Inc. All rights reserved.