Determination of Sapropterin Dihydrochloride in Solid Dosage form by Visible Spectrophotometry

Purpose: The aim of the investigation was to see the simple and sensitive visible spectrophotometric method for the determination of the sapropterin dihydrochloride either in bulk or tablet dosage forms. Method: A simple, sensitive indirect visible spectrophotometric method has been developed for the estimation of sapropterin dihydrochloride in bulk and dosage forms. The method is based on the oxidation of drug with excess N-Bromo succinimide and determining the unreacted NBS with an oxidisable dye Celestein blue by spectrophotometrically at 522nm Results: Beer's law obeyed in the concentration range of 4-12 μg/ml. No interference was observed from the usually existing additives in pharmaceutical formulations and the applicability of the method was examined by analyzing kuvan tablets containing SAP. Conclusion: The reported methods for its assay involve sophisticated equipment, which are very costly and pose problems of maintenance. To overcome these problems, the use of visible spectrophotometric technique is justifiable. The statistical data indicates the accuracy, reproducibility and the precision of the proposed method.