UCSB team makes toxic transdermal drugs safer with salt formulation

Propranolol converted into a transparent liquid salt--Courtesy of UCSB

Drugs designed to be absorbed into the skin have the potential to be toxic due to the organic solvents contained within them. The drugs often need to be combined with these solvents to be effective, but the resulting compound can be harmful.

Researchers at the University of California in Santa Barbara have formulated drugs as liquid salts to enable delivery through the skin without the toxicity associated with organic solvents. Even drugs that show toxicity on their own can be mitigated with a salt formulation, the university says. The antihypertensive drug propranolol is one of these toxic compounds, and the counter ions in a liquid salt can shield the charge in the drug.

The salt formulation could be used in transdermal patches to both enhance the drug's transport through the skin and make the patch safer overall.

The scientists published their findings in the journal Technology.

"An ideal drug liquid salt would need to permeate through the skin as an associated ion pair," lead author Michael Zakrewsky said in a statement. "Eventually, however, the drug and the counter ion must dissociate in blood to preserve drug's therapeutic efficacy. We show that these attributes can be balanced through careful selection of counter ions. This technology presents an exciting new, patient compliant solution for treating diseases."

- here's the release
- and here's the Technology abstract