Spectrophotometric Determination of Hydralazine Using p -DimethylaminobenzaldehydeO.A. Adegoke* and C.E. Nwoke Department of Pharmaceutical Chemistry, Faculty of Pharmacy University of Ibadan, Ibadan, Nigeria (Received 10 March 2007, Accepted 26 September 2007) A new spectrophotometric method for the assay of hydralazine hydrochloride in bulk and dosage forms has been developed. The procedure is based on a condensation reaction between alcoholic solution of hydralazine and acidic solution of p-dimethylaminobenzaldehyde to generate an instant greenish-yellow coloured product. The hydrazone formed absorbed visible light strongly and optimal detector response was obtained at a wavelength of 470 nm with a molar absorptivity of 3.652 � 103 l mol-1 cm-1. Optimization of temperature and time revealed 30 �C and 10 min as the best conditions for optimal color formation, while methanol was found to be�the most suitable alcohol as diluting solvent. The reaction product is stable for at least 24 h. Beer�s law was obeyed in the concentration range of 2-10 μg ml-1. Recovery studies over three days gave a mean recovery of 101.87% with a relative standard deviation of 1.29%. There was no interference from commonly used tablet excipients. There was no significant difference between the results obtained with the new method and the BP iodimetric method (p > 0.05). The proposed method is simple, sensitive, rapid and economical, and could find application as an in-process quality control method for hydralazine.� Hydralazine hydrochloride, p-Dimethylaminobenzaldehyde, Condensation, Alcohols, Spectrophotometry � Keywords: |
