Stability of 5-Fluorouracil in an extemporaneously compounded ophthalmic solution

5-Fluorouracil (5-FU) is used in the treatment of a variety of ophthalmic conditions, including glaucoma, pterygium, retinal detachment and premalignant eye lesions. Specifically for the treatment of pterygium, intravitreal injections of 5-FU have been extemporaneously compounded by pharmacists and typically stored in syringes. No data exist concerning the chemical and physical stability of these solutions. With this in mind, the stability of 5-FU (1mg/0.1mL) in 0.9% sodium chloride injection prepared in the hospital pharmacy laboratory at the University of South Carolina was studied with respect to time and temperature. Admixtures of 5-FU were aseptically prepared and stored in 1-mL tuberculin syringes. The stability of these solutions was evaluated in a freezer, in a refrigerator, at room temperature and in an oven set at 40 deg C. Immediately after prepareation, samples were collected to determine initial concentration using a stability-indicating high-performance liquid chromatography method and to assess the pH of the solution. The same tests were repeated after one, three, five and seven days of storage. Samples were also visually inspected at these times for signs of physical incompatibility. Tuberculin syringes stored at each of the temperatures showed no signs of physical incompatibility (precipitate) or loss of drug. There was also no appreciable change in pH of the solution over the study period. This study showed that aseptically prepared 5-FU ophthalmic solutions packaged in tuberculin syringes can be stored safely for up to seven days at temperatures ranging form -10 to 40 deg C/