[Epinephrine stability in solutions for intra-ocular irrigations].

PURPOSE

Epinephrine may be used for ocular irrigation during ophthalmic surgery when diluted in balanced saline solutions. In aqueous solution, epinephrine breakdown depends on pH, light, temperature, oxidating agents and increases with time.

METHODS

The stability of epinephrine in plastic bags prepared in low concentrations (1 mg/L) was studied by HPLC analysis with UV detection, completed with pH determinations, performed after storage (protected from light) in various conditions: at room temperature (+25 degrees C), at +4 degrees C (in a refrigerator), at -20 degrees C (in a freezer). Spontaneous defreezing at room temperature was compared to accelerated thawing in a microwave oven.

RESULTS

Epinephrine diluted in ocular irrigation solutions (1 mg/L) was stable for 2 days at room temperature, 14 days at +4 degrees C and 35 days at -20 degrees C. Microwave thawing did not alter the stability of epinephrine.

CONCLUSION

The preparation of epinephrine solutions for intra-ocular irrigation may be centralized if the bags are stored less than two weeks in a refrigerator and less than one month in a freezer.