3D-printed pills are on the way, and they will resemble design objects, serving to release active medical ingredients in the body in a controlled manner. A group of computer scientists from the Max Planck Institute for Informatics in Saarbrücken, Germany, and the University of California at Davis have developed a process that combines computation and 3D printing to produce tablets that dissolve in liquids over a specified period of time, writes the German institute in a press release.
- Scientists are using 3D printing techniques to produce pills.
- The researchers have demonstrated that a tablet with a computer-modeled form releases an active ingredient relatively exactly in the intended time period.
For a drug treatment to be successful, it must be possible to adjust the concentration of the active ingredients in the body to a desired level. While this is easier to achieve through intravenous infusion, it gets more complicated when tablets are administered instead. One possibility would be to produce tablets from different components with varying concentrations of active ingredients. But such tablets would be challenging to make. The great advances in 3D printing technology have provided a more viable option. Complex shapes can be created with relatively little effort, including tablets in various geometric shapes. So, the tablet’s shape is the only factor controlling the release of an active ingredient if it is evenly distributed in the carrier material.
Inverse design for tablet shape
A research group led by Vahid Babaei, Research Group Leader at the Max Planck Institute for Informatics, and Julian Panetta, Professor at the University of California at Davis, is using mathematical modeling and experiments to determine which tablet shape releases the desired quantity of an active ingredient during dissolution in the digestive tract, thus ensuring the necessary level of the active ingredient in the body. The team is applying an inverse design and so-called topology optimization for the first time. In this method, which was developed to create mechanical components, the properties of a geometric figure are first defined.
So in the case of tablets, the researchers first define the temporal profile in which the tablet should release its active ingredient. Then, they calculate the shape that has precisely this release profile. To do this, they use a model that records how geometric figures with different forms dissolve in a liquid. The calculated structures sometimes resemble salt crystals, sometimes diatoms, and even extravagant design objects. The team now prints these shapes from a water-soluble material used commercially in 3D printing. The researchers have demonstrated that a tablet with a computer-modeled form releases an active ingredient relatively exactly in the intended time period. These experiments involved dissolving various tablets in water and determining the concentration of the substance in the solution via its light transmission. To ensure that even tablets with bizarre shapes can still be swallowed, producing them from a soft carrier material or encasing them in a fast-dissolving capsule is possible.
Optimization for mass production
However, finding the optimal tablet shape that sets a desired drug level in the body is not the only strong point of the inverse design; it can also take into account how the manufacturing process constrains the choice of shapes. After all, while 3D printing makes it relatively easy to produce arbitrary structures, it is not economical enough for mass production. But, scientists can modify the inverse design conditions so that only shapes that can be created by extrusion are calculated. In this standard industrial process, a liquid mass is pressed through a template, which gives the material strand a shape and solidifies; the strand is then cut into shorter sections. In this way, an inverse design could lead to greater shape diversity not only in pharmaceuticals but also, for example, in the production of fertilizer or catalyst bodies for chemical production.