Simple spectrophotometric method for estimation of disodium edetate in topical gel formulations

A simple, sensitive, cost-efiective and reproducible UV-spectrophotometric method has been developed and validated for the estimation of disodium edetate in topical gel formulations. Solution of disodium edetate reacts with ferric chloride to form complex in 0.1 N HC1 giving λmax at 270 nm. Beer's law was obeyed in the concentration range of 5-50 μg/mL (r2 = 0.9997). The limit of detection and limit of quantitation were found to be 1.190 and 3.608 pg/mL, respectively. The results show that the procedure is accurate, precise, and reproducible (relative standard deviation < 1%), while being simple and less time consuming. The study concluded that the UV-spectrophotometric method could be used for the quantification of disodium edetate in pure form as well as in pharmaceutical formulations.