RESUMEN
OBJECTIVES: The study evaluated the stability of three combinations of oxycodone and ketamine diluted in normal saline (NS) after storage for 7â days at 23°C and exposed to light. METHODS: The stability of three mixtures of oxycodone and ketamine (oxycodone 0.4â mg/mL+ketamine 40â mg/mL, oxycodone 10â mg/mL+ketamine 0.1â mg/mL and oxycodone 10â mg/mL+ketamine 40â mg/mL) in NS stored in a polypropylene syringe and a polyvinyl chloride (PVC) bag was studied. The physical characteristics, including pH, colour and precipitation, were evaluated. The samples were analysed in triplicate by a stability-indicating high-performance liquid chromatography method. RESULTS: There was no significant change in the pH values of any solution. No precipitation or change in colour was observed. All formulations maintained more than 95% of the initial concentration of each drug on day 7. No trace of degradation products was detected. CONCLUSIONS: Ketamine (0.1-40â mg/mL) combined with oxycodone (0.4-10â mg/mL) is physically compatible and chemically stable for 7â days when diluted with NS, packaged in polypropylene syringe or PVC bag and stored at 23°C.