A high pH based reversed-phase high performance liquid chromatographic method for the analysis of aminoglycoside plazomicin and its impurities

• Published in: Journal of pharmaceutical and biomedical analysis 2012-07, Vol.66, p.75-84
• Main Authors: Tan, Li, Wlasichuk, Kenneth B., Schmidt, Donald E., Campbell, Robert L., Hirtzer, Pam, Cheng, Lisa, Karr, Dane E.
• Format: Article
• Language: English
• Subjects: Aminoglycoside; Analysis; Analytical, structural and metabolic biochemistry; Anti-Bacterial Agents - analysis; Anti-Bacterial Agents - chemistry; Biological and medical sciences; Chromatography, High Pressure Liquid - methods; Drug Contamination; Fundamental and applied biological sciences. Psychology; General pharmacology; High pH based mobile phase; Hydrogen-Ion Concentration; Limit of Detection; Mass spectrometry; Mass Spectrometry - methods; Medical sciences; Pharmacology. Drug treatments; Plazomicin (ACHN-490); Reproducibility of Results; RP-HPLC; Sensitivity and Specificity; Sisomicin - analogs & derivatives; Sisomicin - analysis; Sisomicin - chemistry
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2012.03.003

A reversed-phase high performance liquid chromatographic (RP-HPLC) method has been developed for the aminoglycoside (AG) plazomicin (ACHN-490). This method employed a high pH mobile phase (pH>11) with a gradient of 0.25M ammonium hydroxide in water and acetonitrile, an XBridge C18 column and UV detection at 210nm. Although the molar UV absorption of plazomicin is weak, the high pH conditions of this method allow for higher loadings, which compensates for the inherent low UV sensitivity. Under these high pH conditions, impurities and degradants were base line separated from plazomicin. The mobile phases used for this method allowed for on-line mass detection for the impurities and degradants. The RP-HPLC method has been validated in terms of specificity, linearity and range, accuracy, and precision. The analytical method met specificity requirements of a homogenous peak with no interferences from the blank or from the known impurities in plazomicin. The linearity of the method for the plazomicin impurity determination was excellent, with a coefficient of determination (r2) of 0.9993, over the freebase (FB) concentration range of 0.0025–3.0mg/mL. The method is capable of detecting impurities down to 0.1% of the peak area of plazomicin. A single point standard at a concentration of 1.0mg/mL FB was validated over the range of 50–150% for quantitation of the freebase content (the assay) in bulk drug substance. The mean recoveries of FB are in the range 98.6–102.0% with a mean RSD (relative standard deviation)