Determination of bencycloquidium bromide, a novel anticholinergic compound, in rat tissues by liquid chromatography-electrospray ionization mass spectrometry.

First, a liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method for quantification of bencycloquidium bromide (BCQB) in rat tissue homogenates was developed and validated, which would support investigation on drug distribution into tissues in animal models. 1-ethyl-bencycloquidium bromide was used as the internal standard (IS). Sample preparation in tissue homogenates was achieved by using solid phase extraction on a 3 mL C(18)-cartridge column. Chromatographic separation was analyzed on a Hanbon Lichrospher 5-C(18) column. The mobile phase consisted of methanol-40 mM ammonium acetate buffer-formic acid (75:25:0.25, v/v/v) which was pumped at 1.0 mL min(-1). BCQB was determined using electrospray ionization in a single quadrupole mass spectrometer. LC-ESI-MS was performed in the selected ion monitoring (SIM) mode using target ions at m/z 330.2 for BCQB and m/z 344.2 for the IS. The assay was linear from 3.015 ng mL(-1) to 301.5 ng mL(-1) of BCQB in rat tissue (liver, kidney, lung, trachea, heart, spleen, stomach, intestines, brain, muscle, testicle, ovary and fat) homogenates. The lower limit of quantification (LLOQ) was 3.015 ng mL(-1) of BCQB in all tissue homogenates. Acceptable precision and accuracy were obtained for concentrations over the entire standard curve ranges for tissue homogenates. The method was used to successfully quantify BCQB in rat tissue homogenates for a tissue distribution study of BCQB in rats after intranasal administration.