# Influence of Light Irradiation on the Degradation of Dezocine in Injections

## TL;DR

This study investigates how light exposure affects the breakdown of dezocine, an opioid analgesic, in injections and identifies two degradation products.

## Contribution

The study identifies two new photodegradation products of dezocine and their formation mechanisms under light exposure.

## Key findings

- Dezocine degrades into two products under light: one is an oxidation product, and the other is a dimer.
- Degradation increases with higher light intensity and occurs more under ultraviolet than visible light.
- Understanding these degradation products can improve drug safety by reducing harmful impurities.

## Abstract

Dezocine, which is well-known as an analgesic, had about 45% share of the Chinese opioid analgesic market. Since drug products containing impurities could bring serious health consequences, it was important to control the generation of impurities and degradation products in the dezocine product. In this study, two kinds of photodegradation products (i.e., degradation product 1 and degradation product 2) in the dezocine injection were isolated using high-performance liquid chromatography. The possible structures of the photodegradation products were identified using both high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. In addition, the possible generation mechanism showed that degradation product 1 was the oxidation product of dezocine, and degradation product 2 was the coupled dimer of dezocine. Finally, we found that the degradation rate of dezocine increased with the increase in light intensity. Moreover, the degradation of dezocine easily occurred under ultraviolet light in comparison with visible light. A deeper insight into the generation of the photodegradation products in the dezocine injection would directly contribute to the safety of drug therapy based on the dezocine injection by minimizing the degradant/impurity-related adverse effects of drug preparations.