In vitro studies of the interaction between cetirizine and H₂ receptor antagonists using spectrophotometry and reversed-phase high-performance liquid chromatography

摘要

Cetirizine, a second-generation H₁ receptor antagonist, is used for the treatment of allergic disorders. For some of these diseases, combined H₁ and H₂ therapy generally is more effective than treatment exclusively with H₁ or H₂, although this synergistic effect has not been found in all studies. Moreover, extensive in vivo studies have investigated the effects that the coadministration of the H₂ receptor antagonists have on the pharmacokinetics and pharmacodynamics of the H₁ receptor antagonists. The current study therefore adopted an in vitro approach to investigate the interaction of cetirizine with commonly administered H₂ receptor antagonists (i.e., cimetidine, ranitidine, and famotidine) in simulating body fluids at different pH levels and at 37°C using reversed-phase high-performance liquid chromatography (RP-HPLC) and ultraviolet (UV) spectrophotometry. An RP-HPLC method also was developed and validated for the simultaneous determination of these drugs. The mobile phase consisted of methanol:water (80:20) pumped at a flow rate of 1 mL/min. The chromatogram was monitored at 230 nm. The results from the UV spectrophotometry and RP-HPLC clearly indicated that the availability of cetirizine was unaffected by simultaneous administration of H₁ and H₂ receptor antagonists. Hence the two drugs can be safely administered with one another.