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By Howard Chen and Rakesh Gollen

Howard Chen-finalRakesh GollenThe fact that many compounds from current discovery programs are poorly water-soluble requires special formulation considerations. Among various strategies to enhance the apparent solubility of these compounds, amorphous solids have proven to be effective and been shown to exhibit higher solubility and faster dissolution rate, which leads to enhanced oral bioavailability. However, amorphous solids by themselves are seldom stable enough to exist in drug products; therefore, they are mostly formulated in suitable polymeric matrices to form amorphous solids dispersion. Many drug products using this technology have been approved by the Food and Drug Administration for commercial distribution in the recent years.

Polymers play a critical role in amorphous solids dispersion to stabilize amorphous active molecules and maintain super-saturation once the drug is in solution. However, what polymer to use in amorphous solids dispersion remains a great challenge, and the selection of the polymer is still largely an empirical exercise. A lot of effort in the early formulation stage is dedicated to finding the right polymer. Specifically both academia and industry have made great progress toward elucidating the interactions between polymer and active molecule in recent years, so one might establish rational selection criteria for the polymer in order to minimize the actual experimentation and accelerate the development process.

If your research interests are in this area, please join us in the symposium What a Guess! How to Predict Which Polymer Is the One for My Amorphous Solids Dispersion at the 2015 AAPS Annual Meeting and Exposition, in Orlando. In this session, Raj Suryanarayanan, Ph.D., will discuss Molecular Mobility in Amorphous State: Implications on Physical Stability and Marcio Temtem, Ph.D., will present Screening Methodologies for the Development of Spray-Dried Amorphous Solid Dispersions. Through the two speakers’ presentations and the subsequent roundtable discussion, we hope to stimulate discussions amongst ourselves and to conceive new approaches to this question. We look forward to seeing you there. Happy learning!

Howard Chen, Ph.D., is a senior scientist at Upsher-Smith Laboratories, Inc. He has more than four years of industrial experience in formulation and process development and is currently serving the Physical Pharmacy and Biopharmaceutics section as the cochair of the newsletter committee.
Rakesh Gollen is currently pursuing his Ph.D. from Long Island University, with a major in Drug Metabolism and Pharmacokinetics, under the supervision of David Taft, Ph.D. His research focus is on the predictions of pharmacokinetic parameters in special population, using the physiologically based pharmacokinetics modeling approach.