Bioperformance improvement: Small particles and optimal polymorphs

The average molar mass of active substances in crop protection as well as i n pharmaceuticals has grown almost tenfold in the last century. In general, large molar masses are a drawback when looking at bioavailability. There a re several strategies to overcome the problem of low bioavailability. Two o f those strategies will be discussed in this paper: (i) Increasing the diss olution rate of the solids by increasing the specific surface and (ii) incr easing the solubility by choosing an optimal polymorph or an amorphous subs tance. It will be shown what physicochemical measurements are useful to pre dict which excipients will stabilize suspensions of particles as small as 5 00 nm. In relation to optimal polymorphs, the importance of the optimal cho ice will be highlighted and examples of reliable stabilization of the amorp hous form will be given.