Stability of fumagillin in an extemporaneously prepared ophthalmic solution

The stability of fumagillin 70 mu g/mL (as the bicyclohexylammonium crystal ) in an extemporaneously prepared ophthalmic solution was studied. An ophthalmic solution of fumagillin 70 mu g/mL was prepared by combining 1 29 mg of fumagillin bicyclohexylammonium crystals with 20 mt of 0.9% Sodium Chloride Injection, USP, and 20 mt of an ophthalmic irrigating solution. T he solution was stored in 12 sterile semiopaque dropper bottles; 4 bottles were stared at 25 degrees C exposed to light, 4 were stored at 25 degrees C in the dark, and 4 were stored at 4 degrees C in the dark. Samples were ta ken on days 0, 7, 14, 21, and 28 and analyzed by high-performance liquid ch romatography. Sterility was tested as well. In the solutions stored at 25 degrees C, 17-30% of the initial drug concent ration was lost during the first week. The solution protected from light an d stored at 4 degrees C lost about 12% of active drug by week 4. There was no change in color or odor in any of the solutions and only a minor change in pH over the study period. There was no evidence of microbial growth in a ny of the solutions tested. Fumagillin 70 mu g/mL (as the bicyclohexylammonium crystal) in 0.9% sodium chloride injection and an ophthalmic irrigating solution containing benzalk onium chloride was stable in the dark for 14 days at 4 degrees C.