Spectroscopic characterization of in vitro interactions of cetirizine and NSAIDS

Cetirizine (anti-allergy agent) and non-steroidal anti-inflammatory drugs (NSAIDs; anti-inflammatory agents) are co-administered drugs. Cetirizine, a P-glycopretein substrate may be affected by the use of NSAIDs. In the present work, quantification of cetirizine in the presence of commonly co-administered NSAIDs such as diclofenac sodium, ibuprofen, flurbiprofen, tiaprofenac acid, meloxicam and mefenamic acid were studied using the RP-HPLC technique. A high-throughput HPLC method for the analysis of cetirizine was developed, validated in the presence of NSAIDs and was further used to study the interactions of cetirizine in the presence of NSAIDs at four different pH levels. Purospher Star, C18 column (5 μm, 25 cm × 0.46 cm) with a mobile phase of methanol/water (90:10 v/v, pH adjusted to 3.5) at a flow rate of 1.0 mL/min and a wavelength of 240 nm was used. The synthesis of cetirizine in the presence of NSAIDs was carried out, and complexes were characterized using infrared (IR) and nuclear magnetic resonance (NMR) techniques. The method was found to be applicable in serum and was found useful for therapeutic purposes. The differences in availabilities of cetirizine with NSAIDs at three pH levels clearly indicated the interactions of afore mentioned drugs. The findings suggested further studies on the co-administration of these two drugs simultaneously in order to know the pharmacokinetic and pharmacodynamic profiles of the drugs. It is highly recommended to have a suitable time lapse between the oral uses of these drugs.