Identification and quantitation of impurities from benorilate (Salipran) by high-performance liquid chromatography
Chevalier, G.; Rohrbach, P.; Bollet, C.; Caude, M.
Journal of Chromatography 138(1): 193-201
1977
ISSN/ISBN: 0021-9673 PMID: 19488 Document Number: 120535
High-performance liquid chromatography is used for impurity identification and quantitation encountered in a new antalgic, benorylate (or Salipran), an ester of aspirin with paracetamol. Gradient elution is carried out using a stationary phase consisting of porous 10-.mu.m silica beads bonded to alkylnitrile (Micropak CN) and a mixture of hexane-methylenechloride-methanol-acetic acid with varying methanol percentage as mobile phase. The following impurities were separated from benorylate: acetylsalicylic anhydride, aspirin, acetylsalicylsalicylic acid, salophene, amino-4-phenylacetoxy-2-benzoate, paracetamol and p-aminophenol. The repeatability of the analysis is good with a standard variation of 0.54% for benorylate (7 injections). Detection is by UV absorption at 254 nm and detectability is between 2 .cntdot. 10-9 mol for P-aminophenol and 4 .cntdot. 10-11 mol for salophene.