Indirect Spectrophotometric Micro Determination of Catecholamine Drugs in Dosage Forms Using Safranin O Dye and N-bromosuccinimide.

Abstract

Objectives: The present work aims to develop a simple, sensitive, and fast spectrophotometric method for the determination catecholamine drugs namely, adrenaline, methyldopa, and dopamine in pure and dosage forms.

Method: The proposed method is based on the oxidation of the drug compounds by an excess amount of the oxidizing agent N-bromosuccinimide, the remainder of which bleaches the safranin O dye which is measured at 535 nm.

Results: The estimation limits were 0.1-16, 0.5-9, and 0.5-18 μg/ml, with molar absorptivity values of 2.84×10⁴, 5.32×10⁴, and 3.06×10⁴ L/mol.cm with good accuracy and precision, as the average recovery % was 100.55%, 102.04%, and 98.44% for adrenaline, methyldopa, and dopamine, respectively, and the relative standard deviation was better than 2.1 for all drugs. The standard addition method was applied for both adrenaline and dopamine, and the results indicated the method is free from additive interference. The method has been applied successfully for the determination of the above drugs in their pharmaceutical formulations.

Conclusion: The method has been applied successfully for the determination of catecholamine drugs in their pharmaceutical formulations, with good accuracy and precision. The standard addition method was applied, and the results indicated the method is free from additive interferences.