Stability of 5% vancomycin ophthalmic solution prepared using balanced salt solution after freezing for 90 days

Area of Science:

• Ophthalmology
• Pharmaceutical Sciences
• Microbiology

Background:

• Ophthalmic infections require effective antimicrobial agents.
• Vancomycin is a critical antibiotic for treating serious bacterial eye infections.
• Stability data for extemporaneously prepared vancomycin ophthalmic solutions are essential for clinical use.

Purpose of the Study:

• To assess the physicochemical and microbiological stability of a 5% vancomycin ophthalmic solution.
• To determine the optimal storage conditions for this compounded ophthalmic preparation.

Main Methods:

• Aseptic preparation of six batches of vancomycin 50 mg/mL eyedrops using balanced salt solution (BSS).
• Storage of samples at -20°C for 90 days, followed by 30 days at 5°C after thawing.
• Analysis using high-performance liquid chromatography (HPLC) for vancomycin concentration, alongside tests for pH, osmolarity, particle formation, color, turbidity, and sterility.

Main Results:

• No significant changes in pH, osmolarity, color, or turbidity were observed.
• Vancomycin concentration remained within 90%-110% of the initial value throughout the study period.
• No particle formation or microbial growth was detected, confirming both physicochemical and microbiological stability.

Conclusions:

• A 5% vancomycin ophthalmic solution prepared with BSS is stable when stored frozen at -20°C for 90 days.
• The compounded formulation maintains stability for 30 days when refrigerated at 5°C after thawing.