Bioperformance Improvement: Small Particles and Optimal Polymorphs


  • Rolf Hilfiker Solvias AG, Klybeckstrasse 191, CH-4002 Basel
  • Markus von Raumer Solvias AG, Klybeckstrasse 191, CH-4002 Basel
  • André Geoffroy Solvias AG, Klybeckstrasse 191, CH-4002 Basel
  • Fritz Blatter Solvias AG, Klybeckstrasse 191, CH-4002 Basel
  • Hans-Walter Haesslin Syngenta Crop Protection Muenchwilen AG, Im Breitenloh 180, CH-4333 Münchwilen



Adsorption isotherm, Amorphous, Bioavailability, Formulation, Ostwald ripening, Polymorphism


The average molar mass of active substances in crop protection as well as in pharmaceuticals has grown almost tenfold in the last century. In general, large molar masses are a drawback when looking at bioavailability. There are several strategies to overcome the problem of low bioavailability. Two of those strategies will be discussed in this paper: (i) Increasing the dissolution rate of the solids by increasing the specific surface and (ii) increasing the solubility by choosing an optimal polymorph or an amorphous substance. It will be shown what physicochemical measurements are useful to predict which excipients will stabilize suspensions of particles as small as 500 nm. In relation to optimal polymorphs, the importance of the optimal choice will be highlighted and examples of reliable stabilization of the amorphous form will be given.




How to Cite

R. Hilfiker, M. von Raumer, A. Geoffroy, F. Blatter, H.-W. Haesslin, Chimia 2001, 55, 699, DOI: 10.2533/chimia.2001.699.



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