Refractive Index of Powders

The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. This is a very important property of a material or compound, that may characterize a purity or composition of a mixture. The refractive index of a drug is a very important property of a drug product or API to know for the pharmaceutical industry because the size of drug particles is regulated in many cases. Existing laser particle size counters may estimate particle size if the refractive index of the particle material is known.
Normally the refractive index of a liquid or a gas is easy to measure using a suitable refractometer. However, to measure the refractive index of a fine powdered solid material is a challenge.
Have been developed techniques allowing measurement of the refractive index of solid materials, but most of them require a sample of material be manufactured in the required shape. Most solid organic compounds such as drugs may not be made as a uniform, transparent blocks. We use so-called Becke line microscopic method to determine the refractive index of powdered material.
The material is often soluble in the measurement media, so we have developed a differential dynamic method and instrumentation to measure a refractive index of powdered materials.
Please use the contact page to order refractive index test of your material.