Study of in vitro poorly soluble drug solubility into fasted state simulated intestinal fluid reflective of in vivo gastrointestinal variability

Solubility and dynamic light scattering (DLS) studies of three poorly soluble drugs (naproxen, indomethacin and phenytoin) in simulated intestinal fluid (SIF) were carried out in order to calculate the number of drug molecules per micelle based on the assumption of monodisperse spherical micelles. As the total amphiphile concentration increased in the SIF the solubility of the drug also increased. The size of the micelles formed decreased with increasing amphiphile concentration in combination with drug and the number of drug molecules per micelle decreased. Further work is planned to provide more information of the particle size and geometry of the drug loaded micelles.