Robust Raman measurement of hydrogen peroxide directly through plastic containers under the change of bottle position and its long-term prediction reproducibility.

Hydrogen peroxide concentration in antiseptic solutions has been non-destructively measured with the use of wide area illumination (WAI) scheme by applying a laser beam directly through a plastic container. The prediction accuracy was comparable to that from the use of quartz cell instead of a plastic bottle as well as near-infrared (NIR) prediction result in the previous study. Although the position of a plastic bottle was artificially changed in three-dimensional directions up to +/-10 mm to simulate real situation of practical measurement, the prediction accuracy was not degraded within +/-5 mm positional variation. This robust prediction performance was powered by the merits of WAI scheme that could provide improved reproducibility by illuminating large sample areas as well as less sensitivity of sample placement by the design of long focal length. Moreover, the prediction accuracy was successfully maintained over a long period of time. Finally, the prediction was also reproducible under the situation of laser power variation. The overall results demonstrate that WAI Raman scheme can provide robust and non-destructive quantitative analysis for not only hydrogen peroxide in antiseptic solution, but also other active pharmaceutical ingredients in diverse containers.