Some parameters describing the dissolution rate of salicylic acid at controlled pH

Rates of dissolution of salicylic acid have been determined at constant pH in the absence of buffer salts by use of a pH-stat. The dissolution rate increased with increasing pH up to a maximum of pH 4·0. An increase in stirring speed brought about an increase in dissolution rates at each pH. Diffusion layer thickness and diffusion coefficients have been determined utilizing viscosity and density measurements.