Chemical Indexes And In-Vitro Solubility

Different chemical indexes have been proposed in the literature, in order to predict the influence of the chemical composition of mineral fibers on their properties. One of these properties is the acellular in-vitro dissolution behaviour (solubility) in synthetic lung fluids at pH 7.4, which has been shown to be a reliable predictor of the results of expensive chronic long-term in-vivo tests conducted up to now with fibres. The aim of the investigation was to assess if the in-vitro solubility could easily be predicted through conventional chemcial indexes already reported in the literature, such as the following: nonbridging oxygen (NBO); optical basicity (OB); free enthalphy.