and 14 w v u03b1 cyclodextrin in water for injection purposes and stirred for 24 hours at room temperature esmolol and optionally additionally u03b1 cyclodextrin are dissolved in a final concentration of 5 w v esmolol or 14 7 4 2 1 and 0 w v u03b1 cyclodextrin in water for injection purposes and stirred for 24 hours at room temperature esmolol and optionally additionally hydroxypropol u03b2 cyclodextrin are dissolved in a final concentration of 5 w v esmolol or 7 and 0 w v hydroxypropyl u03b2 cyclodextrin in water for injection purposes and stirred for 24 hours at room temperature a parenteral solution was produced in accordance with the recipe set out in table 1 with solution described in examples 1 to 3 accelerated stability tests were carried out at a temperature of 75 u00b0 c after 0 24 45 and 70 hours samples were taken which were diluted with distilled water 20 u03bcl sample 180 u03bcl water the accelerated breakdown was determined by hplc as follows for the qualitative and quantitative analyses a hitachi elite lachrom hplc device with a diode array detector and a waters nova pak c18 4 u03bcm 3 9 u00d7 150 mm column were used the mobile phase consisted of a h 3 po 4 10 g l in water adjusted to ph 2 35 with triethylamine tea and b acetonitrile the gradient used is set out in table 2 the flow rate was 1 ml minute the injection volume 20 u03bcl esmolol hydrochloride was detected at 274 nm the retention time of esmolol hydrochloride was on average 3 9 minutes that of the principal degradation product u201c contaminant a u201d in table 3 below was.