[Use of an in vitro lipolysis model to evaluate type I lipid formulations]

The distribution fate and solubilization behavior of indomethacin through the intestinal tract were investigated with in vitro lipolysis model, by comparing the Capmul MCM and Labrafil M 1944 CS type I lipid formulations. The results showed that the more favorable solubilization was in the aqueous digestion phase from each lipid formulations for indomethacin. The lipolysis rate and extent were decided with chemical constitution of the lipid excipients, which meant that less indomethacin was transferred from the long chain polar oil lipid solution into the aqueous digestion phase. Increasing the concentration of indomethacin in the lipid formualitons from a solution to a suspension led to a linear increase in the concentration of indomethacin attained in the aqueous digestion phase from lipid formulations. This study also implied that adverse effects of the lipolysis rate and extent on drug absorption were could be taken into consideration when screening lipid formulations. Lipid suspensions likely had better enhancement of drug absorption. Last, this study demonstrated that a potential basis for optimizing and assessing type I lipid formulations and also researching in vivo-in vitro correlations of lipid formulations were provided by an in vitro lipolysis model.