Background and Importance In our establishment, an excursion temperature occurred on our freezer containing the hospital preparation including vancomycin eye drops 25 mg/mL. Due to the lack of data, a quarantine of the eye drops was necessary, resulting in a time interval without eye drops preparation. It was necessary to quickly obtain vancomycin eye drops from the other hospitals. Remember that vancomycin eye drops are indicated for the treatment of bacterial keratitis and corneal abscesses.

Aim and Objectives We would like to create four scenarios with different thawing times (0.5h, 2h, 6h and 12h) to imagine different situations can meet users of eye drops to check the stability of the eye drop after 7 days.

Material and Methods After total defrosting the eye drop have been put back to the freezer. After an interval time of at least 48h at -20°C the eye drop was thawed and stored in the fridge condition between 2 and 8°C for 7 days to mimic a normal use. The assay of vancomycin and degradation products has been determined by HPLC at the end of the first thawing time (J0) and at day 0, 3 and 7 of the fridge storage for each batch (D0, D3 and D7). One batch per scenario was tested, each batch contained three samples and each sample was assayed in triplicate.

Detection of the analyte was performed by UV and mass spectrometry (λ=280nm and 725 Da). Likewise, detection of degradation products was carried out by diode array UV and mass spectrometer detector (210 nm to 400 nm and 50–1500 Da).

Results With all these scenarios, we demonstrated that vancomycin eye drops is stable at D7 after 12 hours of thawing. The average variation in vancomycin concentration is less than 5%. No degradation products were observed.

Conclusion and Relevance This physico-chemical study could be reproduced for our other hospital eye drop preparation (ceftazidime and amikacine) which are also used for corneal infections. Then, a microbiological study could be done in the same condition to prove sterility of eye drops after a thawing cycle. These first promising results will permit to avoid quarantine after unintentionally thawing of frozen eye drop preparations.

Conflict of Interest No conflict of interest.