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# FDA’s PHASE Characterizes New Opioids
- URL: https://www.fdaweb.com/fdas-phase-characterizes-new-opioids/
- Published: 2019-04-10T12:00:00.000Z
- Updated: 2026-09-15T01:19:39.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5143828

As part of FDA’s role in combatting the opioid crisis, CDER has developed a Public Health Assessment via Structural Evaluation (PHASE) methodology to provide a structure-based evaluation of a newly-identified opioid’s risk to public safety. Writing online in *Clinical Pharmacology and Therapeutics*, seven CDER staffers [say](https://ascpt.onlinelibrary.wiley.com/doi/epdf/10.1002/cpt.1418?ref=fdaweb.com) PHASE uses molecular structure to predict biological function. Then, software predictions provide the primary and secondary biological targets of the new drug. And, finally, molecular docking estimates the binding affinity at the identified biological targets.

“The multicomponent computational approach coupled with expert review provides a rapid, systematic evaluation of a new drug in the absence of *in vitro* or *in vivo* data,” the article says. “…One challenge presented by the opioid crisis is that many new drugs of abuse lack proper regulatory control and small modifications to a controlled substance may evade prosecution. PHASE can proactively inform law enforcement and the public with vital information regarding the new substance by providing a mechanism for characterizing the structural similarity of newly identified drugs with currently scheduled drugs and predicting the impact of structural modifications on likely biological targets.”