Selective and Validated Spectrophotometric Assay for Microgram Determination of Ganciclovir with 1-fluoro-2, 4-dinitrobenzene and N-Bromosuccinimide Reagents

Two simple, sensitive, selective, accurate, precise and economical methods (method A and B) have been developed for the quantitative estimation of ganciclovir in bulk drug and its pharmaceutical formulations. In method A, an aqueous solution of ganciclovir reacts with 1-fluoro-2, 4-dinitrobenzene (Sanger’s reagent) at borate buffer pH 9 and forms a yellow color complex and absorbance was measured at 354 nm. In method B, N-bromosuccinimide (NBS) used as an oxidimetric reagent and dye methyl orange was used as a spectrophotometric reagent. The method involves adding a measured excess of NBS to ganciclovir in acid medium followed by determination of residual NBS by reacting with a fixed amount of methyl orange and measuring the absorbance at 508 nm. The Beer’s law was obeyed in the concentration range of 0.2-0.6 μg/ml, 1-5ìg/ml for method A and B respectively. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard-addition method. The recoveries of ganciclovir tablets are in the range 99.24, 99.16 respectively. The proposed method is simple, rapid, precise and convenient for the assay of ganciclovir in commercial tablet preparations.