title: Analysis of protamine peptides in insulin pharmaceutical formulations by capillary electrophoresis.
abstract: Protamines are a group of highly basic peptides that are sometimes added to insulin formulations to prolong the pharmacological action. In this study, different methods were investigated to identify protamine in insulin formulations. Capillary electrophoresis in aqueous and non-aqueous media was tested to separate these peptides with very close amino acid sequences. Different buffers (phosphate or formate, both acidified) and various additives (principally negatively charged and neutral surfactants) were investigated to optimize peptide separation. Finally, a micellar electrokinetic capillary chromatography method using a capillary of 120 cm effective length and an aqueous background electrolyte made up of 100 mM phosphate buffer (pH 2) and 50 mM Thesit® gave the best results, providing the separation of the four major protamine peptides within 25 min.
authors.affiliation: Laboratory for the Analysis of Medicines, Department of Pharmacy, CIRM, University of Liege, Liege, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Lamalle
authors.affiliation: Laboratory for the Analysis of Medicines, Department of Pharmacy, CIRM, University of Liege, Liege, Belgium.
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Servais
authors.affiliation: Laboratory for the Analysis of Medicines, Department of Pharmacy, CIRM, University of Liege, Liege, Belgium.
authors.forename: Alice
authors.initials: A
authors.lastname: Demelenne
authors.affiliation: Laboratory for the Analysis of Medicines, Department of Pharmacy, CIRM, University of Liege, Liege, Belgium.
authors.forename: Jacques
authors.initials: J
authors.lastname: Crommen
authors.affiliation: Laboratory for the Analysis of Medicines, Department of Pharmacy, CIRM, University of Liege, Liege, Belgium.
authors.forename: Marianne
authors.initials: M
authors.lastname: Fillet
mesh_terms: D002626:Chemistry, Pharmaceutical; D020374:Chromatography, Micellar Electrokinetic Capillary; D019075:Electrophoresis, Capillary; D007328:Insulin / Q000737:chemistry*; D010455:Peptides / Q000032:analysis*; D011479:Protamines / Q000032:analysis*
chemical_list: D007328:Insulin; D010455:Peptides; D011479:Protamines
keywords: Capillary electrophoresis; Insulin formulation; Non-aqueous media; Protamines