Dry Powder Inhalation Could Deliver COVID-19 Antiviral Treatment

A leading antiviral drug currently used to treat patients diagnosed with COVID-19 disease is remdesivir.

However, administering remdesivir is invasive and challenging.

To resolve this delivery issue, scientists at The University of Texas at Austin (UT Austin) are hoping to use their novel thin-film-freezing technology to deliver remdesivir through dry powder inhalation.

This change would potentially make remdesivir treatments more potent, easier to administer, and more broadly available.

The UT Austin’s Division of Molecular Pharmaceutics and Drug Delivery team is led by Robert O. (Bill) Williams III, Ph.D., has investigated varying methods of drug delivery to repurpose existing drugs into more efficacious forms.

Remdesivir is authorized for emergency use in adult and pediatric patients hospitalized with severe disease. Originally developed to treat the Ebola virus disease, remdesivir has shown promising results treating COVID-19 in the human airway epithelial cells.

But, the current delivery methods have hindered efforts to provide widespread treatment to a broad range of patients exhibiting life-threatening symptoms.

“Unfortunately, remdesivir is not suitable for oral delivery since the drug is mostly metabolized by the body,” Dr. Williams stated in a press release. “Intramuscular injection also faces challenges, since release rates from the muscles can vary widely.”

A microscopic image of remdesivir powder formulations after the thin-film freezing process. All formulations exhibited a brittle matrix structure of highly porous particles.

To provide remdesivir for other patients beyond the most severely ill, more convenient, and accessible dosage forms for different routes of administration must be quickly developed and tested so patients have more options to get treated.

One way to overcome the poor absorption rates of remdesivir is to deliver it directly to the infection site.

The research team, which includes Sawittree Sahakijpijarn, Chaeho Moon, and John J. Koleng, has developed inhaled forms of remdesivir for protecting and treating the respiratory mode of infection, including an amorphous brittle matrix powder made by thin-film freezing.

Not only would this delivery method allow for wider distribution of an essential antiviral in the fight against COVID-19, but it could also make remdesivir more effective.

“If patients can avoid a hospital visit to begin remdesivir treatment, it can lessen the current strains on our health system, lower cost and provide fewer points of contact with those who are still contagious,” Dr. Williams said.

“More widely available early-stage intervention methods could significantly lessen symptoms before they become potentially life-threatening, providing more hospital beds and ventilators to those who need them the most.”

Previously, on May 1, 2020, remdesivir was issued an Emergency Use Authorization for patients hospitalized with severe COVID-19 disease. Since then, remdesivir has been deployed throughout the USA and in other countries.

And recently, on July 24, 2020, remdesivir was linked to significantly greater recovery and a 62 percent lower death rate by day 14 versus standard treatment in hospitalized adults with severe COVID-19 disease.

The UT researchers’ findings were published on July 27, 2020, as a preprint in bioRxiv. Upon the final study results, the team will submit its full findings for peer review and publication.

The Board of Regents of The University of Texas has licensed IP covering inhaled remdesivir formulations prepared with thin-film freezing to TFF Pharmaceuticals, Inc.

Competing Interest Statement: Moon, Sahakijpijarn, and Williams acknowledge TFF Pharmaceuticals, Inc. for financial support through a sponsored research agreement. All authors are co-inventors on related intellectual property.

CoronavirusToday publishes COVID-19 disease treatment news.