Spectrophotometric determination of adrenaline in pharmaceutical preparations

A new and effective spectrophotometric method was developed for the determination of adrenaline in pharmaceutical preparations for control purposes. The condensation of Mannish reaction between 1 mol of adrenaline with new ligand, 5-benzimino-1,3,4-thiodiazole-2-thione (I) in the presence of 1 mol of p-formaldehyde as the condensing agent with 15-25 ml of dioxin as solvent took place. The precipitate yield was yellowish-brown colored. The new ligand was prepared by the Schiff base reaction of 5-amino-3-H, 1,3,4-thiodiazole-2-thione and 1 mol of benzaldehyde in 15 ml of ethanol as solvent and one drop of glacial acetic acid. The accuracy and precision of this method were determined by analyzed laboratory samples of adrenaline, the results show absolute error ranging from −0.22 to +0.86 and relative errors ranging from ±1.4% to 8.6%. The calibration graph was linear in the range of 2-20 mg l−1 for adrenaline with an S.D equal to 2.17%, and RSD of 2.76% (n = 5; Conc. = 80 mg l−1). This method was successfully applied for the adrenaline determination in commercial pharmaceutical injections for the quality control.