FOURIER-TRANSFORM INFRARED SPECTROMETRY (FTIR) FOR QUALITATIVE AND QUANTITATIVE-ANALYSIS OF AZODICARBOXAMIDE AND ITS POTENTIAL IMPURITIES

Azodicarboxamide was determined by Fourier Transform Infrared (FTIR) a ttenuated total reflectance spectrophotometry FIR-ATR) in dimethyl sul foxide (DMSO) solutions. Validation of the method was made as well on the raw material and on dosage forms (capsules). The linear range for azodicarboxamide determination was from 10 to 40 mg ml(-1) with a corr elation coefficient of 0.9998 (n=15). The presence of flowing agents i n the dosage form did not impair the results. The detection and quanti tation of impurities in azodicarboxamide (diethylazodicarboxylate, 1,2 -dicarbethoxyhydrazine and ethyl formate), which are residual by-produ cts coming from the drug synthesis was performed by transmission FTIR spectrometry in C2Cl4 and CHCl3 solutions. These impurities contain an ester function which make them soluble in non polar solvents unlike a zodicarboxamide. The linear ranges for the determination of these impu rities were validated from 0 to 1000 mu g ml(-1) with Linear correlati on coefficients >0.9994 (n=18). Impurities may be detected down to 5.0 mu g g(-1) and quantified down to 15 mu g g(-1). (C) 1997 Elsevier Sc ience B.V.