Physicochemical and Microbiological Stability of Vancomycin 10-mg/mL Intravitreal Syringes

Bacterial endophthalmitis constitutes a medical emergency due to the possibility of leading to blindness unless treatment is administered quickly. The usual treatment seeks to cover both gram-positive and gram-negative bacteria by intravitreal injections of vancomycin and ceftazidime. In the present work, we sought to determine the physicochemical and microbiological stability of intravitreal syringes of vancomycin 10 mg/mL in order to be able to store them as long as possible to have immediate stock. A study was carried out at different temperatures (room temperature, refrigerator, and freezer) for six months in which the concentration and osmolarity were determined and microbiological growth was observed. Also, an accelerated degradation study was carried out at 42°C for 51 days, where only the concentration was determined. The concentrations were quantified using a high-performance liquid chromatography technique. Vancomycin 10 mg/mL in polypropylene syringes is chemically, physically, and microbiologically stable for six months if stored at -20°C and stable for 14 weeks if stored at 4°C.