Reversed-phase high-performance liquid chromatography of fertirelin acetate and related compounds

Separation of fertirelin acetate (FA) from process impurities, potential degradation products and related peptides including luteinizing hormone releasing hormone has been achieved by reversed-phase high-performance liquid chromatography (HPLC). A number of chromatographic conditions (column type, mobile phase composition, isocratic/gradient elution) and detection systems have been utilized to examine the bulk drug and formulation of FA. Examples of separations designed for potency and impurity determinations are described. Complete recovery of FA is obtained with an isocratic HPLC system. An external standard method is used to determine potency with a precision of less than 1% R.S.D. A gradient HPLC system is used to determine impurities with a precision of ca. 5-10% R.S.D. at the 1-2% impurity level. As little as ca. 0.1% (area%) of related peptides are detected at 214 nm.