High-performance liquid chromatographic assay for prostaglandin E 1 in various ointment vehicles : Separation and stability testing

Abstract

A high-performance liquid chromatographic method for the prostaglandin E 1 (PGE 1) incorporated in white petrolatum, white ointment, hydrophilic petrolatum and Plastibase was investigated. The prostaglandin was separated from the oleaginous vehicles with n-hexane-aqueous acetonitrile. Most of white petrolatum, which is a principal component in the vehicles, remained in the n-hexane layer, and the recovery of the drug from any vehicle attained 100%. The method was applied to stability studies of PGE 1 in white petrolatum and macrogol ointment. In which pure PGE 1 and PGE 1-α-cyclodextrin complex (PGE 1-CD) were incorporated. The drug remained intact for up to 6 months when stored at 5°C. At 25 and 40°C, pure PGE 1 was more stable than PGE 1—CD and both PGE 1 species were more stable in white petrolatum than in macrogol ointment.