Biopharmaceutics and formulation New experimental methods for supersaturation and precipitation

This article briefly introduces a number of experimental methods that can be used to investigate supersaturation and precipitation of small-molecule drugs. Methods include solubility measurements by pH-metric methods; controlled supersaturation studies by pH-metric and UV methods; studies of the solid state using polarised light microscopy; aqueous dissolution under changing pH conditions; and biphasic dissolution. Examples illustrate how the results may be used to guide decision-making during formulation.