Inhalable vaccine to inspire smokers to quit

A small spin-out company formed by the University of Colorado has been awarded a $850,000 (€670,000) grant from the US government to develop a dry powder inhalable version of Nabi's investigational injectable vaccine for nicotine addiction, boosting the product's appeal by eliminating needles.

The grant, awarded to Colorado-based firm Aktiv-Dry, will be used to fund Phase I and Phase II activities following reformulation of NicVAX, Nabi Biopharmaceuticals' vaccine which stimulates the immune system to produce antibodies that bind to nicotine and prevent it from entering the brain, helping people to quit smoking.

According to the US Centers for Disease Control and Prevention (CDC), tobacco use is responsible for more than 440,000 deaths each year, and while 70 to 80 per cent of smokers in the US want to quit, less than five per cent of those who try to quit remain smoke-free at twelve months.

Thus, Nabi believes a needle-free technology that delivers NicVAX to the respiratory tract would facilitate patient compliance, enhance the efficacy of a nicotine vaccine and address potential issues with distribution and use on a world-wide basis.

"The overall approach of the project is really quite simple," said Brian Quinn, president of Aktiv-Dry.

"We will reformulate Nabi's NicVAX injectable vaccine as a stable, dry powder consisting of particles, one to three microns in diameter, that humans can inhale and that can easily be delivered to the lungs."

Aktiv-Dry has developed a supercritical carbon dioxide technology to manufacture pharmaceutically active microparticles used in vaccines that are suitable in size and stability for humans to inhale.

The company's method, titled carbon dioxide-assisted nebulisation with a bubble dryer (CAN-BD), uses carbon dioxide as an aerosolisation aid, allowing drying at lower temperatures than usually needed in conventional spray-drying.

In CAN-BD, a solution or suspension in acetone, alcohol, or water is mixed with carbon dioxide at 100bar to form an emulsion.

Intimate mixing of supercritical carbon dioxide with aqueous protein solutions causes the formation of microbubbles, which are rapidly dried in less than 50C as they mix with pre-warmed nitrogen or air in the drying chamber.

Dry fine powders are collected upon exiting the drying chamber which can be used in needle-free vaccine and drug delivery.

Fine-particle pharmaceutical powders can be rapidly and easily made by this new CAN-BD process, requiring less energy and eliminating residues of toxicologically or environmentally objectionable solvents.

The process is therefore more environmentally benign than traditionally used methods and is superior when thermally unstable materials are being processed.

Aktiv-Dry has also been awarded a $19.5m grant this year by the Grand Challenges in Global Health initiative to develop an inhalable measles vaccine.