Printed medication: the future of pharmaceuticals

Scientists from the University of Michigan have developed technology that can print pure, ultraprecise doses of drugs onto a wide variety of surfaces, in a breakthrough that could one day enable on-site printing of custom-dosed medications at pharmacies, hospitals and other locations.

The research was led by Max Schtein and Olga Shalev, who adapted their technology from an electronics manufacturing technique called organic vapour jet printing. The results have been published in the journal Nature Communications.

The process begins by heating the active pharmaceutical ingredient — usually a powder — and evaporating it to combine it with a stream of heated, inert gas like nitrogen. The evaporated medication travels, along with the gas, through a nozzle pointed at a cooled surface. The medication then condenses, sticking to the cooled surface in a thin crystalline film. The formation of the film can be tightly controlled by fine-tuning the printing process.

The end result is that the researchers can print multiple medications into a single dose on a dissolvable strip, microneedle patch or other dosing device, in a process requires no solvents, no additives and no post-processing. Furthermore, their printed medication has been show to destroy cultured cancer cells in the lab as effectively as medication delivered by traditional means, which rely on chemical solvents to enable the cells to absorb the medication.

This microscopy image shows the crystal structure of ibuprofen, printed onto a silicon film using organic vapour jet printing. Image credit: Max Shtein.

The researchers say their technique may be useful for a variety of drug delivery applications, such as for patients who must now take multiple medications every day. Shtein suggested, “A doctor or pharmacist can choose any number of medications, which the machine would combine into a single dose. The machine could be sitting in the back of the pharmacy or even in a clinic.”

One advantage of the technique is that it can print a very fine crystalline structure over a large surface area, which helps printed medications dissolve more easily — and opens the door to a variety of potential new drugs that today are shelved because they don’t dissolve well when administered via conventional approaches.

“Pharma companies have libraries of millions of compounds to evaluate, and one of the first tests is solubility,” said Shtein. “About half of new compounds fail this test and are ruled out. Organic vapour jet printing could make some of them more soluble, putting them back into the pipeline.”

Research assistant Siddharth Suresh Borsadia prints fluorescein crystals onto a cooled glass plate using organic vapour jet printing. Image credit: Levi Hutmacher, Michigan Engineering.

The tight control over solubility may also be useful in the drug testing process, when potential new drugs are applied to cultured cells in a lab. Today, most compounds must be dissolved in a chemical solvent before they’re applied to cells. The new technique could enable printed medications to dissolve easily in the water-based medium used to culture cells, without the need for a solvent.

“When researchers use solvents to dissolve drugs during the testing process, they’re applying those drugs in a way that’s different from how they would be used in people, and that makes the results less useful,” said Anna Schwendeman, an author on the paper. “Organic vapour jet printing could make those tests much more predictive, not to mention simpler.”

While it will be some years before mass-market drugs are being printed, Shtein believes that the drug characterisation and testing applications may come to fruition more quickly — internally in pharmaceutical companies.

“One of the major challenges facing pharmaceutical companies is speed to clinical testing in humans,” said Gregory Amidon, an author on the paper. “This technology offers up a new approach to accelerate the evaluation of new medicines.”

The team is currently exploring additional applications for the technology and plans to collaborate with experts in pharmaceutical compound design and manufacturing, as well as those working on treatments. Eventually, they envision vapour jet printing being scaled to mass production, including roll-to-roll continuous manufacturing.