(130c) Embedded Droplet Printing for Spherical Crystallization of Pharmaceuticals

We present the application of a newly developed technique, embedded droplet printing in yield-stress fluids (1), to the formation of uniform spherical pharmaceutical particles. Yield-stress fluids are rheologically complex materials that are solid-like below a critical stress but undergo a dramatic drop in viscosity and flow above their yield stress. Printing droplets that are embedded inside a yield-stress fluid enables their processing in the absence of exterior influences including convection and solid boundaries. This makes embedded droplet printing ideal for performing sensitive processes like pharmaceutical crystallization.

In this study, we crystallize various drug-excipient systems using embedded droplet printing methods. We demonstrate the advantages of our technique in obtaining particles that are as spherical and uniform as possible, key targets in the manufacturing of pharmaceutical materials. The powders we produce show significant improvement over conventional materials in terms of their flowability and processability, and we believe embedded droplet printing can help pave the way for the manufacturing of more exquisite and targeted pharmaceutical products.

1. A. Z. Nelson, B. Kundukad, W. K. Wong, S. A. Khan, P. S. Doyle, Embedded droplet printing in yield-stress fluids. Proc. Natl. Acad. Sci. 117, 5671–5679 (2020).