Stability of vancomycin in an extemporaneously compounded ophthalmic solution

Area of Science:

• Ophthalmology
• Pharmaceutical Sciences
• Drug Stability

Background:

• Ophthalmic infections require effective antibiotic formulations.
• Vancomycin is a critical antibiotic for treating serious bacterial eye infections.
• The stability of vancomycin in ophthalmic vehicles is crucial for therapeutic efficacy.

Purpose of the Study:

• To evaluate the stability of vancomycin hydrochloride at 31 mg/mL in an artificial tears solution.
• To determine the optimal storage conditions and duration for vancomycin in this ophthalmic vehicle.

Main Methods:

• Vancomycin hydrochloride was prepared at 31 mg/mL in a hydroxypropyl methylcellulose-based artificial tears solution.
• Solutions were stored at -10°C, 4°C, 25°C, and 40°C.
• Stability was assessed by visual inspection and high-performance liquid chromatography analysis over 60 days.

Main Results:

• Solutions remained clear and colorless at -10°C, 4°C, and 25°C.
• Crystalline particles formed by day 3 at 40°C.
• Vancomycin retained >90% concentration for 45 days at -10°C, 21 days at 4°C, and 7 days at 25°C.

Conclusions:

• Vancomycin 31 mg/mL in artificial tears demonstrates acceptable stability for specific storage durations and temperatures.
• Refrigerated storage (4°C) or freezing (-10°C) is recommended for longer vancomycin stability in this formulation.
• The formulation is not stable at elevated temperatures (40°C).