Spectrophotometric and spectrofluorimetric determination of trimebutine

Two simple, rapid and sensitive spectrophotometric and spectrofluorimetric methods have been developed for the detn. of trimebutine in bulk drug, pharmaceutical prepns. and in urine.  The first method depends on ion-​pair complex reaction of trimebutine with two indicators, bromophenol blue (BPB) and thymol blue (TB)​, in methanol.  Different variables affecting the reactions were studied and optimized.  The colored products of the drug with bromophenol blue and thymol blue were extd. and measured at 415 and 425 nm, resp.  Beer's law was obeyed in the concn. ranges 7-​60 μg ml^-​1 and 5-​30 μg ml^-​1 for BPB and TB resp.  The spectrofluorimetric method depends on the condensation of malonic acid and acetic anhydride under the catalytic effect of trimebutine.  The condensation product gave emission light measured at 430 nm (excitation at 390 nm)​.  Calibration range gave good correlation in the range of 0.8-​80 ng ml^-​1.  The proposed methods were applied for estn. of the drug in different pharmaceutical prepns. without interference from common encountered additives.  Percentage recoveries ranged from 98.4​% to 101.5​%.  The fluorimetric method was applied for the detn. of drug in urine and gave good recoveries ranging from 98.45 to 102.15​% for spiked concn. in the range 0.01 to 1.00 mg ml^-​1 and the measured concn. ranged from 0.8 to 80 ng ml^-​1.