Cetirizine dihydrochloride interaction with some diclofenac complexes

Area of Science:

• Pharmaceutical Chemistry
• Coordination Chemistry
• Analytical Chemistry

Background:

• Cetirizine dihydrochloride is a widely used antihistamine.
• Diclofenac sodium is a common non-steroidal anti-inflammatory drug (NSAID).
• Understanding drug-drug interactions and their complex formation is crucial for pharmaceutical development.

Purpose of the Study:

• To investigate the interaction between cetirizine dihydrochloride and diclofenac sodium.
• To characterize the adducts formed, particularly in the presence of metal ions.
• To elucidate the bonding interactions and structural features of the resulting complexes.

Main Methods:

• Infrared (IR) spectroscopy
• Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy
• Mass spectrometry
• Thermogravimetric (TG) analysis
• Elemental analysis

Main Results:

• Strong adduct formation between cetirizine dihydrochloride and diclofenac sodium was observed.
• Stable ternary (with divalent metals like Ca, Mg, Zn) and quaternary (with trivalent iron) compounds were formed.
• Ionic bonding occurred between diclofenac's carbonyl ion and cetirizine's piperazine ring.
• Coordination was confirmed at the NH of diphenylamine via shifts in IR bands (nuNH, deltaNH, nuC-N).
• Results were corroborated by TG and elemental analysis.

Conclusions:

• Cetirizine dihydrochloride and diclofenac sodium form stable complexes with significant molecular weight.
• These interactions are robust and can occur even when diclofenac is coordinated to metal ions.
• The study provides insights into the chemical interactions and structural characteristics of these drug adducts.