Nephelometry measures the forward scattered light when passing solutions. This can be used to determine particles in solution as they increase light-scattering. The particles may be derived from drugs at their limit of solubility or from microbes. Hence, determination of drug-solubility and microbial growth are two main applications for nephelometry.
Using a microplate-based nephelometer, the NEPHELOstar® Plus, solubility of the antifungal substances Econazole-nitrate and ciclopirox-olamine each complexed with Cyclodextrins was monitored and showed a higher solubility than their uncomplexed form. The Cyclodextrin-complexes were studied regarding their antifungal activity on Candida albicans and revealed a higher efficiency of the Econazole complex as compared to the ciclopirox complex.
This study has proven that laser nephelometry in a 96-well microtiter plate can be used as a method for the rapid determination of the solubility of potential drug compounds.