Assay of Sapropterin Dihydrochloride in Tablet Dosage Form Using Aromatic Aldehyde

A simple and sensitive visible spectrophotometric method has been developed for the determination of sapropterin dihydrochloride in pure and tablet dosage forms. This method is based on the condensation reaction of drug with aromatic aldehyde such as Para dimethyl amino cinnamaldehyde (PDAC) in the presence of sulphuric acid in non aqueous medium and formed purple red colored Schiff base product with an absorption maximum of 534nm. The Beer's law obeyed in the concentration range of 10-30µg/ml. The proposed method is applied to commercial available Kuvan tablets and the results are statistically compared with those obtained by the reference UV method and validated by recovery studies.