September 7, 2023 – Convincing kids to take their meds 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 be able to print accurately dosed tablets in child-friendly shapes and flavors. While efforts are focused on two drugs for AIDS in children, the process could be used to print other drugs, including for adults.
Researchers of Britain, Australiaand the University of Texas at Austin are also in the early stages of 3D-printed drug projects. It is a promising venture in the broader pursuit of ‘personalized medicine’, tailoring treatments to each patient’s unique needs.
The mass production of drugs is not suitable for pediatric patients, who often require different dosages and combinations of drugs as they grow. As a result, tablets for adults are often crushed and dissolved in liquid – known as compounding – and given to children. But this can damage the quality of medicines and make the doses less accurate.
“Say the child needs 3.4 milligrams and there’s only a 10 milligram tablet available. Once you manipulate the dosage from solid to liquid, how do you make sure it’s got the same amount of drug?” said co-principal investigator Mansoor Khan, PhD, professor of pharmaceutical sciences at Texas A&M.
Most pharmacies don’t have the equipment to test the quality of compounded drugs, he said. And liquid medicines taste bad because the coating of the pill has been ground away.
“Taste is a big issue,” he says Olive Eckstein, MD, assistant professor of pediatric hematology-oncology at Texas Children’s Hospital and Baylor College of Medicine, who is not involved in the study. “Hospitals will sometimes delay the discharge of pediatric patients because they can’t take their medications orally and have to get an IV formulation.”
Updating pharmaceutical 3D printing
The FDA approved one 3D printed medicine 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, said co-principal investigator Mathew Kuttolamadom, PhD, associate professor of engineering at Texas A&M.
The Texas A&M team uses a different method, without solvents. First, they make a powder mix of the drug, a biocompatible polymer (such as lactose), and a gloss, a pigment that colors the tablet and causes heat to be absorbed. Flavorings may also be added. The mixture is then heated in the printing chamber.
“The polymer should melt just enough. That gives the tablet structural strength. But it must not melt too much, so that the drug can dissolve in the polymer,” says Kuttolamadom.
The tablets are finished with precise applications of laser heat. Using computer-aided design software, the researchers can make tablets in virtually any shape, such as “stars or teddy bears,” he said.
After much trial and error, the researchers printed tablets that don’t fall apart or get soggy.
Now they are testing how different laser scanning speeds affect the structure of the tablet, which in turn affects the rate at which drugs dissolve. Slowing down the laser gives more energy, strengthens the tablet structure and causes drugs to dissolve more slowly, for a longer release in the body.
The researchers hope to develop machine learning models to test different laser speed combinations. Eventually, they could make tablets that combine drugs with different dissolution rates.
“The outside could be rapid-release, and the inside could be extended-release or sustained-release, or even a completely different drug,” Kuttolamadom said.
Older patients who take a lot of daily medications could benefit from the technology. “Personalised tablets can be printed at your local pharmacy,” he said, “even before you leave the doctor’s office.”