Dear Sir. Concerning your issue about the availability of  UV spectra of esmolol and its acid metabolite Esmolol acid . Esmolol (trade name Brevibloc) is a cardioselective beta1 receptor blocker with rapid onset, a very short duration of action, and no significant intrinsic sympathomimetic or membrane stabilizing activity at therapeutic dosages. Esmolol decreases the force and rate of heart contractions by blocking beta-adrenergic receptors of the sympathetic nervous system, which are found in the heart and other organs of the body. Esmolol prevents the action of two naturally occurring substances: epinephrine and norepinephrine. Spectrophotometric Determination of Esmolol Hydrochloride and its acid metabolites . 2,3-Dichloro-5, 6-dicyano-1, 4-benzoquinone, 1-chloro 2,4-dinitro benzene, 2,5-dichloro-3,6-dihydroxycyclohexa-2,5-diene-1,4-dione (chloranilic acid), and sodium 3,4-dioxo-3,4-dihydronaphthalene-1-sulfonate (Folin’s reagent) Using Analytical Reagents were measured at λmax of 460, 430, 410, and 490 nm for four different methods.  For more details you can see the following below links which may help you in your analysis:

http://www.ijacskros.com/artcles/IJACS-M113.pdf

http://iosrjournals.org/iosr-jac/papers/vol5-issue4/A0540109.pdf?id=7283

https://www.wikigenes.org/e/chem/e/59768.html

Thanks

Hello Dr Thanks for the reply, but i was looking for the spectrum, the article you have provided have the caliberation curves.