pH measurement and phosphate determination in pharmaceutical eye drops for eye diseases by digital image analysis

摘要

A method based on Digital Image Analysis (DIA) is described to quantify pH and phosphates simultaneously in eye drops for the treatment of glaucoma and dry eye syndrome. In this work, images acquired with a smartphone were used. For phosphate determination, the colorimetric reaction that uses ammonium molybdate and antimony potassium tartrate was used. The formed blue complex was quantified using the R channel of the RGB color space. The pH was measured using bromothymol blue indicator, which gives a color between yellow and blue. The information of the pH measurement was extracted from histograms of the pictures and a PLS model was performed to quantify the values. All solutions were placed in microtitration wells in which less than 400 mu L of sample are necessary and up to 92 samples can be measured in a single image.