To evaluate the efficacy of 0.5% proparacaine stored at room temperature for 6 weeks.
Six normal dogs, evaluated on a weekly basis for 6 weeks.
Proparacaine stored at 4 °C or at room temperature, was evaluated in the right and left eye of each dog, respectively. Corneal sensitivity was assessed with a Cochet-Bonnet aesthesiometer before and after instillation of proparacaine at each time point.
A statistically significant difference was seen in corneal sensitivity beginning at week 3 for the eyes receiving room-temperature proparacaine compared to refrigerated proparacaine. Differences were not seen between right and left eyes before instillation of proparacaine for any time point, nor for eyes receiving refrigerated proparacaine over the 6 week study period.
Short-term storage of proparacaine at room temperature did not affect efficacy, but storage at room temperature for more than 2 weeks resulted in a decrease in drug effect.