Study of the Effect of Eudragit RSPO on the Photostability of Venlafaxine in a Physical Mixture and in a Melt Form

The effect of Eudragit RSPO on the photostability of venlafaxine in a physical mixture and as a melt was studied. A validated ultra-high-performance liquid chromatography mass spectrometry method was used to determine the content of venlafaxine alongside degradation products. The most likely structures of the degradation products were determined by mass spectrometry. The samples were evaluated before and after exposure to ultraviolet A by differential scanning calorimetry and scanning electron microscopy. The kinetic parameters of the decomposition of venlafaxine in the physical mixture and melt form were calculated and comparable to those of venlafaxine as an active pharmaceutical ingredient. The results indicate that the process of venlafaxine decomposition is more than three times slower in the venlafaxine-eudragit melt than in its physical mixture with eudragit and its pure form. The strong photoprotective nature of the tested polymer against venlafaxine in the melt form was also confirmed by differential scanning calorimetry and scanning electron microscopy.

Automated summary

This study investigated the effect of Eudragit RSPO on the photostability of venlafaxine in a physical mixture and as a melt. A validated method using ultra-high-performance liquid chromatography mass spectrometry was employed to determine the content of venlafaxine and its degradation products. The results showed that the decomposition of venlafaxine was more than three times slower in the venlafaxine-eudragit melt compared to its physical mixture and pure form.