Background and Importance Moxifloxacin syringes for intracameral injection are a compounding formula prepared in the Pharmacy Department to prevent endophthalmitis in cataract surgeries.¹ According to the Spanish Good Practice Guides for the preparation of medications in hospital Pharmacy Departments, this compounded formula would have a shelf life of 9 days in the refrigerator (2 °C – 8 °C).² This physicochemical stability study is proposed to improve the efficiency in our Pharmacy Service.

Aim and Objectives To characterise the physicochemical stability of intracameral moxifloxacin 1 mg/0.2 ml syringes stored in refrigeration (2 °C – 8 °C) and protected from light for 90 days.

Material and Methods Three 50 ml batches of moxifloxacin were prepared at different concentrations (1, 2, 4, 5, and 7 µg/ml) in a horizontal laminar flow cabinet using water for injection as a solvent, starting from the commercial eye drop Vigamox 5 mg/ml®.

Concentration measurements of moxifloxacin were carried out on days 1, 3, 7, 15, 22, 30, 60, and 90 using a Perkin Elmmer model Lambda 40 UV/visible spectrophotometer at a wavelength of 290 nm (maximum wavelength of moxifloxacin).

Results Throughout the entire analysis period, the moxifloxacin concentrations determined by the spectrophotometer remained constant and within the values accepted by the United States Pharmacopeia that ensure its physicochemical stability (± 10%). In addition, linearity was met in all measurements with a determination coefficient (R²) > 0.999, indicating that the prepared concentrations of moxifloxacin remained stable over time.

Conclusion and Relevance The formulations of intracameral moxifloxacin 1mg/0.2 ml in water for injection are physicochemically stable at least for 3 months when stored in the refrigerator (2 °C – 8 °C) and protected from light. Further investigation would be advisable to continue with the study in order to extend their shelf life.

References and/or Acknowledgements 1. Anderson J, Young S, Cockerham G, et al. Evidence Brief: Intracameral Moxifloxacin for Prevention of Endophthalmitis After Cataract Surgery. Washington, DC: Department of Veterans Affairs (US); 2022 May. Available from: https://www.ncbi.nlm.nih.gov/books/NBK581595/

2. Ministerio de Sanidad. Guía de buenas prácticas en la administración de medicamentos en servicios de farmacia hospitalaria [Internet]. 2014. Available from: http://www.sefh.es/sefhpdfs/GuiaBPP_JUNIO_2014_VF.pdf

Conflict of Interest No conflict of interest.