Purpose: Commercially available chlorhexidine gluconate (CHG) has a beyond-use date of 24 h. This study evaluated the stability and sterility of 0.05% CHG for 30 days after opening and compared its cost to povidone iodine (PI) for intravitreal injection antisepsis. Methods: 0.05% CHG was aliquoted into 1-mL syringes and stored at room temperature or refrigerated. Turbidity, pH, high-performance liquid chromatography (HPLC), and sterility testing were performed. A cost analysis was conducted. Results: 0.05% CHG remained stable for at least 30 days. All samples had measured turbidity <0.5 nephelometric turbidity units. The pH of all samples remained between 5.0 and 7.0. HPLC demonstrated CHG concentration at day 30 relative to day 0 of 98.52% ± 4.16% at room temperature and 99.99% ± 3.38% at 2°C -6°C. The cost per week to perform 150 injections using 0.05% CHG was $463.25 when opening a new bottle daily compared with $16.73 for 5% PI. This cost decreased to $23.16 when utilizing a bottle of CHG for 30 days. Conclusion: 0.05% CHG remains stable and sterile for at least 30 days after opening. The ability to use CHG for at least 30 days after its opening significantly decreases its utilization expense.
Keywords: chlorhexidine gluconate; endophthalmitis; intravitreal injection; povidone iodine.