The solubility of a potential drug is one of the most important characteristics as water solubility is required to assure activity at site of action. Solubility can be determined by laser nephelometry which detects forward scattered light. If a particle in a solvent (non-solved compound) scatters the light of a laser the signal is increased and reflects the threshold of solubility.
This application note presents the automatic solubility screen for drugs such as Progesterone, Hydrocortizone, Dofetilide and Paracetamol which was achieved by integrating the NEPHELOstar® Plus microplate nephelometer in a liquid handling platform. Test compounds of different concentrations were measured in quadruplicates in 384-well format. A plate of 24 compounds was studied in 75 min and the MARS Software automatically calculated the solubility as well as visualized the evaluation as soluble, non-soluble and partially-soluble by a colour-code.