Determination of (+)-5-(2,3-dihydrobenzofuran-7-yl)-3-methyl-8-nitro-2,3,4,5- tetrahydro-1H-3-benzazepin-7-ol (NNC 01-0687), a novel dopamine D-1 receptor antagonist, in plasma by solid-phase extraction and high-performance liquid chromatography.

A fast and reliable method has been established for the determination of the dopamine D-1 receptor antagonist (+)-5-(2,3-dihydrobenzofuran-7-yl)-3-methyl-8-nitro-2,3,4,5-tetrahydro-1 H-3- benzazepin-7-ol (NNC 01-0687) in plasma. A combination of reversed-phase extraction on C18 columns and straight-phase high-performance liquid chromatographic analysis with ultraviolet detection at 287 nm resulted in very clean chromatograms. The limit of quantitation was about 1 ng/ml of plasma. Validation of the method showed good selectivity, linearity, recovery, accuracy and precision. Several modifications of the method were possible with little or no influence on the assay.