Physicochemical Stability of an S-Ketamine-Dexmedetomidine Anesthetic Mixture: An In Vitro Study

Background Although anesthetic drug admixtures are widely used in clinical practice, the physicochemical stability and photodegradation profile of the S-ketamine-dexmedetomidine (KET-DEX) admixture have not been previously characterized. This study evaluated the physicochemical stability of the KET-DEX admixture under ambient and ultraviolet (UV) light exposure. Methods The admixture (0.25 mM) was stored under ambient conditions or exposed to UV light for 24 hours. Physicochemical stability was assessed by high-performance liquid chromatography with diode-array detection (HPLC-DAD), while degradation products were characterized using mass spectrometry. Stability was evaluated based on chromatographic profile, degradation products, and physicochemical parameters. Results The KET-DEX admixture remained physicochemically stable for 24 hours under ambient conditions, with no evidence of significant degradation or drug interaction. In contrast, UV exposure induced progressive photodegradation of KET, whereas DEX remained stable. Conclusions The KET-DEX admixture demonstrated physicochemical stability under standard laboratory conditions but should be protected from UV light during storage and handling. These findings provide the first evidence of the admixture's stability profile and establish a foundation for future investigations addressing its clinical applicability, efficacy, and safety.