Eye drop particle size and shape

Three bottles of eye drops (ISV-502) containing micro particles in suspension were submitted for analysis. One contained the sample mixed with H2O, another was mixed with 5% polysorbate and the last one was not diluted. The required measurements were count and size distribution.

Figure 1. Original image at 400X (0.1176 micron / pixel). This image shows a typical field where many of the particles are out of focus.

Figure 2. After a first pass of detection, particles in focus were identified. Artifacts were eliminated and a first measurement was performed on the remaining particles and agglomerations.


Figure 3. All particles and clusters were copied in red and separated further. Only features likely to be composed of a unique particle were kept and a second measurement was performed.


Figure 4. Outline of particles as measured in red bitplane. The outline view mode allows to see which particles were separated.


To demonstrate that the Clemex Vision image analysis system can perform size and shape measurements on samples of eye drops containing very fine particles (~1 to 5 µm). Particles of this size are close to the limit of optical microscopy, which explains the difficulty in capturing clear images of the sample.


Length, Circular Diameter, Aspect Ratio, Sphericity, Width and Ellipsoidal Volume measurements were performed on each feature. Automated statistics and graphs were generated during the run and were accumulated for the whole sample. With its versatile and powerful toolbox, Clemex Vision was able to provide the information required and quantify the particles present in the eye drops.