Sept. 7, 2023 – Convincing kids to take their medicine could become much easier. Researchers at Texas A&M University are developing a new method of pharmaceutical 3D printing, with pediatric patients in mind.
They hope to print precisely dosed tablets in child-friendly shapes and flavors. While the effort is focused on two drugs for pediatric AIDS, the process could be used to print other medicines, including for adults.
Researchers from Britain, Australia, and the University of Texas at Austin are also in the early stages of 3D-printed medication projects. It’s a promising venture in the broader pursuit of “personalized medicine,” tailoring treatments to each patient’s unique needs.
Drug mass production fails to address pediatric patients, who often need different dosages and combinations of medicines as they grow. As a result, adult tablets are often crushed and dissolved in liquid – known as compounding – and given to children. But this can harm drug quality and make doses less precise.
"Suppose the child needs 3.4 milligrams and only a 10-milligram tablet is available. Once you manipulate the dosage from solid to liquid, how do you ensure that it has the same amount of drug in it?" said co-principal investigator Mansoor Khan, PhD, a professor of pharmaceutical sciences at Texas A&M.
Most pharmacies lack the equipment to test compounded drug quality, he said. And liquified drugs taste bad because the pill coating has been ground away.
"Flavor is a big issue,” said Olive Eckstein, MD, an assistant professor of pediatric hematology-oncology at Texas Children's Hospital and Baylor College of Medicine, who is not involved in the research. “Hospitals will sometimes delay discharging pediatric patients, because they can't take their meds orally and have to get an IV formulation.”
Updating Pharmaceutical 3D Printing
The FDA approved a 3D-printed drug in 2015, but since then, progress has stalled, largely because the method relied on solvents to bind drug particles together. Over time, solvents can compromise shelf life, according to co-principal investigator Mathew Kuttolamadom, PhD, an associate professor of engineering at Texas A&M.
The Texas A&M team is using a different method, without solvents. First, they create a powder mixture of the drug, a biocompatible polymer (such as lactose), and a sheen, a pigment that colors the tablet and allows heat to be absorbed. Flavoring can also be added. Next, the mixture is heated in the printer chamber.
“The polymer should melt just enough. That gives the tablet structural strength. But it should not melt too much, whereby the drug can start dissolving into the polymer,” Kuttolamadom said.
The tablets are finished with precise applications of laser heat. Using computer-aided design software, the researchers can create tablets in almost any shape, such as “stars or teddy bears,” he said.
After much trial and error, the researchers have printed tablets that won’t break apart or become soggy.
Now they are testing how different laser scan speeds affect the structure of the tablet, which in turn affects the rate at which drugs dissolve. Slowing down the laser imparts more energy, strengthening the tablet structure and making drugs dissolve slower, for a longer release inside the body.
The researchers hope to develop machine learning models to test different laser speed combinations. Eventually, they could create tablets that combine drugs with different dissolve rates.
“The outside could be a rapid release, and the inside could be an extended release or a sustained release, or even a completely different drug,” Kuttolamadom said.
Older patients who take many daily medications could benefit from the technology. “Personalized tablets could be printed at your local pharmacy,” he said, “even before you leave your doctor's office.”