Abstract
Purpose :
There are different dye solutions for chromovitrectomy on the market which do not just differ from each other with respect to the dye but also in buffer additives used and in packaging. The aim of this study was to investigate the chemical stability of different dyes by UV/VIS spectroscopy and the influence of the various parameters on it.
Methods :
Buffer solutions with deuterium oxide, polyethylene glycol 3350, and D-mannitol, respectively, as additives were prepared containing one of the following dyes: 1.5 g/L acid violet 17, 0.25 g/L brilliant blue G, 1.3 g/L bromophenol blue, and 1.5 g/L trypan blue. To mimic a certain storage period samples were incubated for 400 hours at 80 °C which corresponds to approximately two years according to the Van 't Hoff equation. After 100, 200, 300, and 400 hours of incubation samples were taken for analysis using UV/Vis spectrometry, pH measurement, and osmometry.
Results :
Samples of the dyes which were filled in 2 ml vials without any additive showed that after 400 hours at 80 °C brilliant blue G (80%), bromophenol blue (85%) and trypan blue (88%) are subjected to only minor degradation. In sharp contrast to these three dyes, acid violet 17 (0%) is totally degraded.
Second, we determined the influence of packaging on the stability of the different dye solutions. The results demonstrated that dye solutions filled in syringes are much more stable than in vials (Figure 1). Again, this observation applies to all dyes except acid violet 17. This dye is degraded independent of packaging.
The last experimental series analyzed the variation of pH value, during ageing. Only the pH value of the D-mannitol containing buffer considerably drops below 7.0.
Conclusions :
With respect to stability dye solutions filled in syringes should be preferred to solutions filled in vials to slow down oxidative degradation processes. Notably, solutions containing acid violet 17 should be used with caution because of degradation processes or a drop in pH-Value in combination with D-mannitol.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.