Derivative spectroscopy has been utilised for the determination of amphotericin in various biological matrices including plasma, serum, urine and brain tissue. Whilst these methods have all been shown to be suitable for the determination of the drug in these matrices it has been reported that the application fails in the case of highly icteric plasma, this being due to the presence of high concentrations (>50 mu M) of bilirubin. This paper details the application of ratio spectra derivative spectroscopy to overcome the interference of bilirubin with amphotericin in such situations.
Millership, J., McCaffrey, F., & Teirney, D. (2008). A novel application of ratio spectra derivative spectroscopy for the determination of amphotericin in highly icteric plasma. Journal of Pharmaceutical and Biomedical Analysis, 48(2)(2), 408-413. https://doi.org/10.1016/j.jpba.2007.12.043