Abstract
Purpose :
Vancomycin ophthalmic solution is used to treat keratitis caused by methicillin-resistant Staphylococcus aureus. No commercial preparations of ophthalmic eye drops of vancomycin are available and, it needs to be aseptically prepared from IV injection by a pharmacy licensed for compounding. The aim of this study was to test the stability of extemporaneously compounded vancomycin ophthalmic solution stored at room temperature and under refrigeration using HPLC and microbiological assay
Methods :
Vancomycin ophthalmic solution was aseptically prepared in 3 different vehicles (Normal Saline, BSS and PBS). The ophthalmic solutions were stored either at room temperature or at 4οC in a refrigerator. The solutions were sampled at day 3, 7, 14 28, 42 and 56 for chemical analysis of vancomycin using The United States pharmacopeia HPLC method and for vancomycin activity using microbiological assay. Freshly prepared solutions of vancomycin were used as standards for both the assays.
Results :
HPLC analysis revealed a minimal decrease (<5%) in vancomycin concentration in ophthalmic solutions up to the tested time point of 56 days. No significant difference in vancomycin concentration was observed in the solution stored either at room temperature or in the refrigerator at 4οC. Additionally, there was no impact of the vehicle on vancomycin stability because no significant difference in the vancomycin concertation was observed when saline, BSS or PBS was used as compounding solution. The HPLC analysis was further supported by microbiology assay and no differences in the zone of inhibition was observed between vancomycin solutions compounded in the 3 different vehicles and tested at the various time points.
Conclusions :
Our data suggest that extemporaneously compounded vancomycin ophthalmic solutions in normal saline, PBS and BSS are stable up to 2 months after compounding and the stability is not impacted by storage conditions either at room temperature or refrigeration at 4οC.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.