If you go onto any 3D model marketplace and search for “pill case,” you can find all sorts of 3D printable cases that allow you to sort and store your daily medications. Pill cases like those are a literal lifesaver for many people who have multiple pills to take on a daily basis and have trouble remembering which ones need to be taken at which time. It’s possible, though, that pill sorting cases will eventually become obsolete. Numerous research organizations have been working on developing 3D printed pills, with the hope being that one day patients will be able to have all of their needed medicines combined in one tablet.
It’s not just pills, though. Some scientists have been using 3D printing to develop single vaccinescontaining all the antibodies a patient needs, and researchers at the University of Michigan have created a new 3D printing technology that allows them to print precise doses of medication onto dosing devices such as dissolvable strips, similar to breath strips, or microneedle patches.
The printing technique was created through a collaboration between the Michigan Engineering departments of Biomedical Engineering and Chemical Engineering, as well as the College of Pharmacy and the Department of Physics. It was adapted from an electronics manufacturing technology called organic vapor jet printing, which is capable of printing a fine, crystalline structure over a large surface area. When applied to pharmaceuticals, the technique creates a medication that easily dissolves.
Siddharth Suresh Borsadia, Materials Science & Engineering Graduate Student Research Assistant, sets up a printing demonstration combining evaporated Fluorescein with Nitrogen which is jetted, much like a 3D printer, onto a variety of cooled surfaces. [Image: Levi Hutmacher]
“Pharma companies have libraries of millions of compounds to evaluate, and one of the first tests is solubility,” said Max Shtein, Professor of Materials Science and Engineering. “About half of new compounds fail this test and are ruled out. Organic vapor jet printing could make some of them more soluble, putting them back into the pipeline.”
[Image: Levi Hutmacher]
How it works is that the active ingredient, usually a powder, is heated and evaporated to combine it with a stream of heated, inert gas like nitrogen. The gas and evaporated medication travel through a nozzle, which is pointed at a cooled surface. The medication then condenses on that surface and sticks to it in a thin crystalline film. Fine-tuning the printing process can control the formation of the layers of film, and the whole process requires no solvents, additives or post-processing.
“Organic vapor jet printing may be useful for a variety of drug delivery applications for the safe and effective delivery of therapeutic agents to target tissues and organs,” said Geeta Mehta, the Dow Corning Assistant Professor of Materials Science and Engineering and Biomedical Engineering.
The research was documented in a paper entitled “Printing of small molecular medicines from the vapor phase,” which you can access here. The study tested the printed medication on cultured cancer cells in the lab, and found that it destroyed them as effectively as conventional medicines, which require chemical solvents to enable the cells to absorb the medication. This method has promising implications for drug testing, as the medications easily dissolve in the water-based medium used to culture cells without any need for solvents.
“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 assistant professor of pharmaceutical sciences at the University of Michigan and an author on the paper. “Organic vapor jet printing could make those tests much more predictive, not to mention simpler.”
This microscopy image shows the crystal structure of ibuprofen, printed onto a silicon film using organic vapor jet printing. [Image: Max Shtein]
The technique could also allow doctors and pharmacists to combine multiple medications into one easy-to-deliver dose. The 3D printing of mass-market pharmaceuticals is likely years away, according to Shtein, but he believes that the technology may be used for drug characterization and testing much sooner.
“One of the major challenges facing pharmaceutical companies is speed to clinical testing in humans,” said Gregory Amidon, a research professor in the University of Michigan College of Pharmacy and an author on the paper. “This technology offers up a new approach to accelerate the evaluation of new medicines.”
The research team is working on a roadmap for exploring additional applications of the technology, and plans to work with experts in pharmaceutical compound design and manufacturing. Eventually, they hope to scale the technology to mass production.
[Source: University of Michigan]