Dissolution kinetics of griseofulvin in sodium dodecylsulphate solutions

The rate-limiting step in the absorption of poorly water-soluble drugs is often the dissolution process of these compounds. Surface-active agents influence the dissolution process by wetting and solubilizing. In order to study the effect of solubilization, a rotating-disk apparatus was used with griseofulvin as a model drug substance and sodium dodecylsulphate (SDS) as a model surfactant. The dissolution kinetics of griseofulvin in SDS solutions could adequately be described by the convective-diffusion model and the phase-separation model for micellar systems. The calculated micellar diffusion coefficient of SDS was in close agreement with values reported in the literature.