With an ever-increasing demand for mesoscopic particles of pharmaceutical materials, whether microcrystalline or nanocrystalline
colloidal in form, with defined physical and chemical characteristics, the benefits offered by ultrasound-assisted particle-engineering
technologies are valuable. Because ultrasound-assisted technologies are single-stage, solution-to-particle processes and have
the potential to meet the scale-up requirements, attractive solutions are available to address many of the problems in engineering
pharmaceutical materials and particle design.
Ultrasound should have a bright future in industrial processing, crystallization, and particle engineering. True industrial
adaptation of the techniques discussed will necessitate the design and building of new ultrasonication equipment for laboratory
use and production in a safe, effective, and economic manner.
Many processing opportunities can be approached with flow-cell technology. Power ultrasound equipment should find its way
into many manufacturing facilities. New techniques such as SAX and DISCUS could become the default methods for producing perfect
Graham Ruecroft* is chief technical officer, and Dipesh Parikh is a senior scientist at Prosonix, The Magdelen Centre, Robert Robinson Ave., Oxford Science Park, Oxford OX4 4GA, UK, tel.
+44 1865 784244, firstname.lastname@example.org
*To whom all correspondence should be addressed.
1. B. Aungst, "Intestinal Permeation Enhancers," J. Pharm. Sci.
89 (4), 429–442 (2000).
2. A.H.L. Chow et al., "Particle Engineering for Pulmonary Drug Delivery," Pharm. Res.
(3), 411–437 (2007)
3. B.E. Rabinow, "Nanosuspensions in Drug Delivery," Nat. Rev. Drug Discov.
(9), 785 (2004).
4. C. Leuner, J. Dressman, "Improving Drug Solubility for Oral Delivery Using Solid Dispersions," Eur. J. Pharm. Biopharm.
(1), 47–60 (2000).
5. Y. Wu, F. Kesisoglou, S. Panmai, "Nanosizing—Oral Formulation Development and Biopharmaceutical Evaluation," Adv. Drug Deliv. Rev.
(7), 631–644 (2007).
6. Synthetic Organic Sonochemistry, J.L. Luche, Ed. (Plenum Press, New York, 1998).
7. G. Ruecroft et al., "Sonocrystallization: The Use of Ultrasound for Improved Industrial Crystallization," Org. Process Res. Dev.
(6), 923–932 (2005).
8. G. Ruecroft, "Sound Science in Molecules and Particles," Speciality Chemicals Magazine (June), 60 (2008).
9. Prosonix. Entrainment in Anti-Solvent. Br. Patent Application 07.05159.2, 2007.
10. Prosonix, Crystalline Particles Using Immiscible Anti-Solvent: Solvent, Br. Patent Application 07.11680.9, 2007.
11. Glaxo Group Limited, Novel Process, Patent WO/2003/035035, 2003.
12. AstraZeneca, Process for the Preparation of Crystalline Nano-Particle Dispersions, Patent WO/2004/009057, 2004.
13. Syngenta Limited, Process for Preparing a Crystal Suspension, US Patent 6,517,853, 2003.
14. Z. Guo et al., "Effect of Ultrasound on Anti-Solvent Crystallization Process," J. Cryst. Growth
(3–4), 555–563 (2004).
15. C. Virone et al., "Primary Nucleation Induced by Ultrasonic Cavitation," J. Cryst. Growth
(1), 9–15 (2006).