Development of Validated Spectrophotometric Methods for Estimation of Ethacridine Lactate in Pharmaceutical Formulations

Abstract

Ethacridine lactate (EAL) is an antiseptic in solutions of 0.1%. It is also used as an agent for second trimester abortion. Two simple and sensitive spectrophotometric methods (Method A and Method B) were developed for the estimation of EAL in pharmaceutical formulations. Method A is based on the condensation of the primary aromatic amino group of ethacridine lactate with an aromatic aldehyde (p-Dimethylamino- cinnamaldehyde) to form a chromophore with absorption maximum of 600nm. Method B is based on redox reaction followed by complex formation of EAL with IO₃^-Metol reagent to form a stable chromogen, which can be estimated at 520 nm. Method A obeys Beer’s law in the concentration range of 2 to 12 μg/mL and method B in the range of 20 to 100 μg/mL. Interference studies were conducted to see the influence of excipients with the proposed methods. The common excipients usually present in dosage forms do not interfere in the proposed method A and method B. The optical characteristics, regression analysis data and precision of the methods were also calculated. The methods were validated for use in routine quality control of EAL in pharmaceutical formulations.