Activated carbon ‘acts like a slow-release drug capsule’ in drug delivery study

Acyclovir is an antiviral that while effective in treating the herpes virus often results in resistance to the drug and kidney damage after long-term use.

Researchers at University of Illinois at Chicago (UIC) began testing the activated carbon in combination with the drug as a means of determining if the mineral could trap viruses from infecting the eye as activated carbon is known to have purifying effects, according to the UIC researchers, and can trap toxins in its highly porous structure.

Deepak Shukla, professor of ophthalmology, microbiology and immunology, and director of the ocular virology laboratory told us that after positive results in testing the activated carbons ability to trap viruses, “We wanted to see if loading our porous carbon with acyclovir could synergistically enhance the activity of acyclovir. To our surprise, activated carbon was not only able to absorb the acyclovir into its pores but was able to slowly release it over a period of time, conferring protection from herpes infections.”​

The charcoal delivery system, drug encapsulated carbon, is known as DECON. The new approach, according to the researchers, could be applied to prophylactic products as it provides some additional protection from spreading viral infection.

Tejabhiram Yadavalli, co-inventor of the technology and postdoctoral fellow studying herpes viruses at UIC stated, “The activated carbon acts like a slow-release drug capsule. Because it likes to bind with the virus, this gives it additional anti-viral properties.”​

Yadavalli explained, “We think that the charcoal releases particles of acyclovir slowly over time because the herpes virus, as well as other organic molecules and particles, are more attracted to the charcoal than the drug, and as these particles interact with the charcoal they displace and release the drug."​

Both plain activated carbon and activated carbon plus acyclovir were tested on both types of herpes infection, HSV-1 and HSV-2.

The lab reported that dilutions of plain activated carbon reduced the infection of cells when applied to the cells prior to exposure to HSV-1 or HSV-2.

When the combination acyclovir and activated carbon was tested in mice infected with either HSV-1 or HSV-2 researchers stated that it was more effective and faster in reducing inflammation and viral load than acyclovir alone.

Additionally, when combined with the activated carbon, reduction in viral load and inflammation was achieved with fewer doses than with acyclovir alone.

Shukla told us that DECON has shown efficacy in curbing other viruses from the same family as herpes such as porcine pseudorabies virus, and bovine herpesvirus. DECON is currently being tested in delivering other antiviral drugs, peptide therapeutics, and antibody therapies.

“Given that DECON is an excellent delivery platform, we believe its application to carry other antivirals will be equally successful and hence applicable to almost any viral infection,”​ Shukla added.