Cetirizine dihydrochloride interaction with some diclofenac complexes

IR, H-1 NMR and mass spectrometric studies showed that cetirizine dihydrochloride interacted strongly with diclofenac sodium, even when the latter was metal bound, forming high molecular weight stable adducts. These Dew formations were unaffected by the possible steric constraints that may exist because of coordination yet did not have the power to break the formed coordinate bonds. The formed ionic bond took place between the carbonyl ion of diclofenac and the positively charged piperazine ring of cetirizine, forming a ternary compound in the case of the divalent metal clusters (Ca{(dic)(2)center dot 2H(2)O}, Mg{(dic)(2)center dot 2H(2)O}, Zn{(dic)(2)center dot 2H(2)O}) and a quaternary one with the trivalent iron cluster (Fe{dic}(3)center dot 3H(2)O). IR bands assigned to vNH, delta NH and vC-N were shifted to lower frequency values in the spectra of the complexes; thus showing that coordination took place at the NH of the diphenylamine. TG and elemental analysis confirmed these results. (C) 2005 Elsevier B.V. All rights reserved.