Slide 14 Slide showing plasma phenactin versus time curve after various suspensions (redrawn from Prescott, L.F., Steel, R.F., and Ferrier, W.R. 1970 Pharmacol. Ther., 11, 496-504). The effect of particle size on drug absorption is shown in this slide. Generally speaking the smaller the particle size the quicker the absorption. By increasing the particle surface area it is possible to increase the dissolution rate. However very small particle can clump together. Therefore a wetting agent such as Tween 80 can have a beneficial effect on the overall absorption. The intestinal fluids usually contain some materials which can act as wetting agents, however drug dissolution testing in vitro may neglect this effect.

Copyright 2001 David W.A. Bourne