Simultaneous Determination of Prostaglandin E1 and Prostaglandin E1 Ethyl Ester in Hairless Mouse Skin Homogenate by High-Performance Liquid Chromatography

A rapid and specific high-performance liquid chromatographic method was developed and validated for the simultaneous determination of prostaglandin $E_{1}\;(PGE_{1})$ and prostaglandin $E_{1}$ ethyl ester $(PGE_{1}-EE)$ in hairless mouse skin homogenate. The sample treatment procedure involved deproteination and precipitation by acetonitrile. $PGE_{1}$ and $PGE_{1}-EE$ in supernatant were separated in a reversed-phase C18 column without being interfered by other components present in hairless mouse skin homogenate. 9-Anthracenecarboxylic acid was used as an internal standard. The retention times of $PGE_{1}$, 9-anthracenecarboxylic acid and $PGE_{1}-EE$ were, 4.5, 9.5 and 18.0 min, respectively. The assay showed linearity from 1 to $40\;{\mu}g/ml$ for both $PGE_{1}$ and $PGE_{1}-EE$. Precision expressed as RSD ranged from 2.3 to 14.1 % for $PGE_{1}$ and 1.6 to 11.0% for $PGE_{1}-EE$. Accuracy ranged from 100.5 to 119.6 % for $PGE_{1}$ and from 98.0 to 103.7% for $PGE_{1}-EE$. This method was employed successfully to follow the time course of concentrations of $PGE_{1}$ and $PGE_{1}-EE$ in hairless mouse skin homogenate for stability study.