The present paper aims at a complex spectral and physicochemical evaluation of mono[{3-[4-(2-eth-oxyethoxy)-benzoyloxy]-2-hydroxypropyl)-tert-butyl-ammonium] fumarate, the potential ultra-short acting blocker of beta1-adrenergic receptors. The identity of the evaluated compound (labelled as UPB-2) was confirmed by 1H-, 13C-NMR and IR spectral data as well. The estimated physicochemical parameters included melting point data, solubility in various media, purity checking (adsorption thin-layer chromatography), surface activity determination (non-direct Traube stalagmometric method), acidobasic characteristics (pKa value determination by alkalimetric titration), log epsilon values estimation (spectrophotometrically in UV/VIS region) and a study of the influence of acidic and alkaline media towards the stability of UPB-2. Other experimentally estimated values were lipohydrophilic descriptors using RP-HPLC (log k') and the log PexpS in various lipohydrophilic media by the shake flask method. Based on the log Pexp readouts, the ability to permeate across the brain-blood barrier was predicted. For the content determination of UBP-2 the RP-HPLC (reversed-phase HPLC), the method of an internal standard and UV/VIS spectrophotometry at the wavelength of 260 nm (aqueous medium) and at 258 nm (methanolic medium) was applied.