Stability of Voriconazole by Constant-Rate Infusion for Ocular Delivery in Horses

Voriconazole 1% solution is not compatible with constant-rate infusion delivery and the use of other aqueous-based medications may have similar results. Voriconazole 1% solution is stable when stored in the commercial glass vial at controlled temperatures between 23 and 40oC up to 30 days. Authors’ addresses: Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences (Smith, Gilmour); Department of Physiological Sciences, Center for Veterinary Health Sciences (Maxwell); Department of Veterinary Pathobiology, Center for Veterinary Health Sciences (Gull); and Department of Statistics (Payton), Oklahoma State University, Stillwater, OK 74078; e-mail: kathryn.m.smith@okstate.edu.

1. Introduction

The study objective was to establish the effect of storage in a constant-rate infusion (CRI) pump on the sterility and stability of voriconazole 1% solution.

2. Materials and Methods

Nine vials of voriconazole 1% solution^a were prepared. Each vial was used to prime a commercially-available CRI pump and attached subpalpebral lavage system (CRI/SPL unit), with the remaining solution stored in the commercial glass vial. Three CRI/SPL units and their 3 corresponding vials were stored at 23°C, 33°C, and 40°C. Fungal and aerobic bacterial cultures were performed on all solutions on the first and last storage day. Samples obtained at regular intervals were analyzed for voriconazole concentration using high-performance liquid chromatography.

3. Results

No bacterial or fungal contamination was identified in any solution. All solutions stored in the glass vial remained stable throughout the study. Voriconazole concentration significantly increased (by 35–134%) after passage through the SPL and several units became blocked with precipitate (p < 0.05). 

4. Discussion

Voriconazole 1% solution was not compatible with CRI/SPL delivery but remained stable when stored in the commercial glass vial.

Acknowledgments

Supported by Oklahoma State University Research Advisory Committee.

Conflict of Interest

The Authors declare no conflicts of interest.

Footnote

^a Vfend I.V., Pfizer Pharmaceuticals, New York, NY 10017.