Spectrophotometric Assay of Noradrenaline in Pharmaceutical Formulation with Quinalizarin in Aqueous Solution

A simple, rapid and sensitive spectrophotometric method for the determination of noradrenaline was developed. The method is based on the proton transfer reaction with quinalizarin in aqueous neutral solution to form a violet product showing maximum absorbance at 560 nm with molar absorptivity of 6680 l.mol-1.cm-1. The method follows Beer’s law over the concentration range (5.91×10-6 -5.91×10-5) mol.L-1 The accuracy (average recovery) of the method is 99.72% and the precision (RSD) of the method is less than 1.5%.The method was successfully applied for the determination of noradrenaline in pharmaceutical formulation as injection and the results were in a good agreement with the standard addition procedure

Spectrophotometric Determination of Terbutaline Sulphate and Tetracycline Hydrochloride via ion pair Complex Formation Using Eosin Y

A simple, sensitive and rapid spectrophotometric method was developed and validated for the determination of terbutaline sulphate and tetracycline hydrochloride drugs in pure form and pharmaceutical formulations. The proposed method is based on the formation of binary complexes between these drugs and eosin Y in aqueous acetate buffered medium. Under the optimum conditions, the binary complexes showed absorption maxima at 545 nm. Beer's law was rectilinear over concentration range of 0.5-10 and 5-45 μg/mL, R2 were 0.9984 and 0.9988, RSD were ≤ 0.72 and ≤ 0.19 (n=5) with average recovery % 101.42 % and 100.08 % and the average recovery values of pharmaceutical formulations 101.48 and 98.01 for above drugs respectively. The limit of detection (LOD) were 0.030 and 0.613 μg/mL and limit of quantitation (LOQ) were 0.103 and 2.00 μg/mL with molar absorptivity values 3.169 103 and 6.347 103 l. mol-1. cm-1 and the relative standard deviation values ≤0.720 and ≤ 0.19 for both drugs respectively. No interference was observed from the excipients that are commonly present in pharmaceutical formulations. The proposed method was successfully applied to the analysis of terbutaline sulphate tablet and tetracycline hydrochloride capsule in their dosage forms