Quantitative thin-layer chromatographic determination of some prostaglandin-derivatives of the subgroups E₂, A₂ and B₂

Summary

A direct, quantitative, thin-layer chromatographic (TLC) method is described for the separation and determination of a PGE₂-descendant (compound I = PGE₂-desc.), a PGA₂-descendant (compound II = PGA₂-desc.) and a PGB₂-descendant (compound III = PGB₂-desc.) as pure substances and in pharmaceutical preparations. The extraction of the active ingredients is performed in a fully automated apparatus within 5 min. Using TLC compound I (UV-inactive substance) must be converted into compound III so that it can be measured at λ-max. 280 nm. Compound II can be measured both directly at λ-max. 224 nm and after conversion into compound III [1]. The conversion of PGE₂-desc. and PGA₂-desc. into PGB₂-desc. was achieved after spraying the separated PG-spots on the TL-plates with KOH solution and heated. The TLC development was carried out on silica gel 60 F₂₅₄ and measurement was direct on the plates by chromatogram spectrodensitometry using the reflection method. The method is also suitable for stability studies and has also proved useful in the analysis of the prostaglandin-derivatives in various pharmaceutical preparations.