UV and Visible Spectrophotometric Method for the Determination of Leucovorin

Two simple and reproducible UV-Visible spectrophotometric methods were developed for the estimation of leucovorin in pure and injectable dosage forms. The visible method is based on the reaction of leucovorin with Folin-Ciocalteu Reagent (FCR) in the presence of sodium hydroxide which forms a bluish green coloured complex. This mixture was heated for 10 minutes at 70-90 degrees C. The resultant complex after suitable dilution with water exhibited maximum absorption at 724 nm. UV spectrophotometric method was developed and used in the direct estimation of leucovorin in pure and injectable dosage forms. In this method, leucovorin in phosphate buffer (pH 7.7) was mixed thoroughly and measurements were taken at 280 nm. Both these methods are simple, low cost and easy to handle for the quantitative determination of leucovorin in injectable pharmaceutical preparations.