Quantitation of Physostigmine in Plasma by High Pressure Liquid Chromatography,

摘要

We described a new method to estimate physostigmine in plasma. The method utilized a liquid/liquid, ion-pair extraction coupled with normal phase liquid chromatographic analysis and fluoresence detection. The limit of detection was 100 nanograms/millimeter of plasma. Neostigmine methyl sulfate was added before extraction to protect physostigmine from degradation by endogenous enzymes in the plasma, and to improve its stability. Recovery of physostigmine was consistently greater than 80% and averaged 92%. We used the method to examine the stability of physostigmine in plasma stored at -15 C and -80 C. The results indicated that physostigmine can be stored at either temperature for 6 weeks without undergoing significant alterations. Keywords: Physostigmine, Ion-pair extraction, Normal phase chromatography, Fluorescence detection. (kt)