Medications for schizophrenia often need to be taken for a lifetime. But what happens when a drug is sensitive to sunlight? Researchers from Leibniz IPHT and the University of Jena have investigated how exposure to light affects the promising neuroleptic LE404 – and what this could mean for its stability.

Schizophrenia is one of the most severe psychiatric disorders. According to the World Health Organization (WHO), around 24 million people worldwide are affected – approximately 1 in 300 individuals requires long-term medication. LE404 is a new compound that specifically targets dopamine and serotonin receptors, offering a promising alternative to existing medications. However, initial tests revealed that LE404 can degrade when exposed to sunlight.
A team from Leibniz IPHT and Friedrich Schiller University Jena has now examined this effect in more detail. The researchers analyzed the light stability of the compound and identified its degradation products. Their findings could provide valuable insights for the storage, formulation, and application of the medication.

When Active Compounds Become Unstable

The researchers deliberately exposed LE404 to light – using an artificial source that simulates sunlight. After just twelve hours, part of the compound had decomposed. A particularly critical finding: one degradation product was formed exclusively due to light exposure, while another resulted from oxidation in the presence of oxygen.
“If a drug is sensitive to light, that can be a major challenge in pharmacology,” explains Dr. Jonathan Plentz, head of the Photonic Thin Film Systems group at Leibniz IPHT. “Not only does storage become more complicated, but there is also the risk of unwanted reactions occurring in the body.”
Using high-resolution mass spectrometry and NMR spectroscopy, the team analyzed the chemical structures of the degradation products. These insights could be crucial for pharmaceutical development: knowing how a medication reacts to light allows for protective measures such as special packaging or modified formulations.

From Solar Cell Research to Drug Stability Studies

Analyzing light-sensitive substances is not new territory for Plentz’s team – but the path to this research was unusual. The group originally focused on developing light-­sensitive materials for solar cells. When ­Leibniz IPHT shifted its focus toward optical health technologies, the team successfully realigned its research. “Our expertise in light-sensitive materials and optical thin films has proven to be highly versatile,” says Plentz. “Transitioning from developing materials for solar cells to investigating drug stability has been an exciting journey for us.”