High performance liquid chromatographic determination of azelastine and desmethylazelastine in guinea pig plasma and lung tissue.

Analytical methods have been developed for the simultaneous quantitation of azelastine (AZ) and desmethylazelastine (DAZ) in guinea pig plasma and lung tissue. The methods require a 1.00 mL plasma sample and a minimum 0.100 g lung sample. Both methods employ liquid/liquid organic extraction and back-extraction into dilute acid. Quantitation is performed by high performance liquid chromatography on a 2 x 250 mm 5 microns Hypersil CPS column using fluorescence detection. The linear quantitative ranges for AZ.HCl and DAZ.HBr in plasma are 0.156-160 ng/mL and 0.313-160 ng/mL, respectively. The linear quantitative ranges for AZ.HCl and DAZ.HBr in lung tissue are 0.039-20 micrograms/g for both.