the eluant of a previously developed stability-indicating liquid chromatographic method for phenylephrine hydrochloride ( i ) , phenylpropanolamine hydrochloride ( ii ) , and guaifenesin ( iii ) was modified to yield a better separation between phenylpropanolamine and the impurity .
C0011782
phenylpropanolamine
C0031495
phenylpropanolamine