Stability study of ready-to-use vancomycin prefilled injections in polypropylene syringes and low-density polyethylene bags for neonates

Abstract

Vancomycin is extensively used to treat methicillin-resistant Staphylococcus aureus infections in neonates. Ready-to-use vancomycin injection solutions prefilled into sterile syringes and bags may help improve operational efficiency. Previous stability studies primarily relied on HPLC for drug content, often lacking concurrent evaluation of antibiotic potency via microbial assay, identification of degradation products, or assessment of sterility at the end of the shelf life. Furthermore, information was limited regarding head-to-head stability comparisons across different container sizes for ready-to-use vancomycin solutions. Therefore, this study aimed to evaluate the physical, chemical, and microbiological stability of a 5 mg/mL vancomycin solution in 5% dextrose by providing a head-to-head comparison across different sized containers (10-, 20-, and 50-mL polypropylene (PP) syringes and a 100-mL low-density polyethylene (LDPE) bag) while assessing both vancomycin content (HPLC) and antibiotic potency (microbial assay) and confirming sterility at the end of the shelf life. The drug solutions in all size containers had a pH range of 3.60–3.64, an osmolality of 245–249 mOsm/kg, a %labeled amount of 99–103% as determined by high-performance liquid chromatography, and an antibiotic potency of 99–101%. The vancomycin solutions were physically and chemically stable for 55 days at 5±3 °C when stored in the 10- and 20-mL PP syringes and 100-mL LDPE bag and protected from light. Under similar storage conditions, the solution in the 50-mL PP syringe had a shelf life of only 30 days at 5±3 °C owing to an exceeding limit for degradation products and impurities. All the solutions were sterile at the end of their shelf life. Therefore, these prefilled vancomycin solutions can be prepared and stored in a pharmacy service unit in a hospital for subsequent administration of the drug to neonates.