title: Fatty acid composition analysis in polysorbate 80 with high performance liquid chromatography coupled to charged aerosol detection.
abstract: The fatty acid (FA) composition of polysorbate 80 (PS80), a sorbitan oleic acid ester copolymerized with about 20mole of ethylene oxide, is typically characterized by gas chromatography. Here, an alternative method was developed. After saponification with potassium hydroxide the FA fraction was collected with liquid-liquid extraction using methyl-tert-butyl ether. HPLC in combination with a Corona® charged aerosol detector (CAD) was applied for the separation and detection. The method was fully validated in terms of specificity, repeatability, limits of quantification, linearity, range, accuracy and robustness. The characterization of 16 different PS80 batches demonstrated variability regarding their FA composition, with e.g. the amount of oleic acid ranging from 67.8±0.7% to 96.6±1.4%. Furthermore, we identified petroselinic acid, a double-bond positional isomer to oleic acid in all batches, an FA not known to pharmacopoeias at present. In addition, 11-hydroxy-9-octadecenoic acid, an oxidation product of oleic acid was identified. Structure elucidation was performed by means of HPLC-MS/MS. In addition, the method was expanded to the evaluation of the free FAs. Having determined the entire FA composition, the acid value according to EP and USP can be calculated.
authors.affiliation: Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Ilko
authors.affiliation: Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Braun
authors.affiliation: Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Wuerzburg, Germany; Current address: Institute for Pharma Technology, University of Applied Sciences Northwestern Switzerland, Gruendenstrasse 40, 4132 Muttenz, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Germershaus
authors.affiliation: Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Meinel
authors.affiliation: Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Wuerzburg, Germany. Electronic address: u.holzgrabe@pharmazie.uni-wuerzburg.de.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Holzgrabe
mesh_terms: D000336:Aerosols; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction; D011136:Polysorbates / Q000737:chemistry* / Q000592:standards; D015203:Reproducibility of Results; D013501:Surface-Active Agents / Q000737:chemistry* / Q000592:standards; D053719:Tandem Mass Spectrometry; D013678:Technology, Pharmaceutical / Q000295:instrumentation / Q000379:methods*
chemical_list: D000336:Aerosols; D005227:Fatty Acids; D011136:Polysorbates; D013501:Surface-Active Agents
keywords: 11-hydroxy-9-octadecenoic acid; Acid value; Charged aerosol detection; Fatty acids; High performance liquid chromatography; Petroselinic acid; Polysorbate 80