3D Printed Tablets for Controlled Drug Release
Researchers at the University of the Basque Country have developed a technique that allows them to 3D print pharmaceutical tablets using different types of starch. By modifying the types of starch used and the shape of the tablets, the team can fine-tune drug release to be either rapid or slow. This includes full release of the encapsulated drug in as little as ten minutes to as long as six hours, providing significant scope to address a wide variety of therapeutic situations. The technique could allow for more personalized medicine for patient cohorts who require specialized dosing regimens, such as young children and elderly people. Another benefit of the approach is the ability to deliver hydrophobic drugs, which typically are challenging to formulate because they won’t dissolve in water.
Oral dosing of drugs in the form of ingestible tablets is in some ways the simplest way to deliver a drug, requiring a patient to simply swallow a tablet. However, there is a lack of diversity in the doses available for certain patients. Such patients will often require different doses compared with standard adult doses, and may benefit from different release profiles. This is also true of patients with differing levels of disease severity, and genetics and gender can also play a role in the most appropriate dosing and release profile for a specific patient.
However, tablets are often available in a ‘one-size-fits-all’ formulation that does not account for these nuances. To address this, these researchers have developed a method to 3D print tablets and fine tune release to create a more personalized approach to oral medication.
To create their customs pills, the researchers turned to a natural material, starch. “We were able to prepare tablets based on three types of starch -two types of maize starch (normal and waxy) and one type of potato starch- with different geometries and loaded with a non-soluble drug,” said Kizkitza González, one of the creators of the new types of tablets.
By using different types of starch, the researchers were able to drastically alter the release profile of the included drug. “We observed the importance of the botanic origin of the starch in practically all the properties, such as porous microstructure, the formation of a stable network or the release of the drug,” said González. “In the case of normal maize starch, drug release is instantaneous and the drug is fully released within 10 minutes; in the case of waxy maize starch and potato starch, release is more continuous and can take up to 6 hours for full release. We were also able to demonstrate the importance of tablet geometry in drug release.”
Finally, by combining two different types of starch, the researchers were able to create bi-phasic release, allowing for more advanced applications. “Tablets combining different types of starch were also printed,” said González. “In this case, release takes place in two stages. For example, in the case of an infection, in an initial stage using normal maize starch, a medicine could be released immediately to alleviate pain, and in a subsequent stage, with either of the other two types of starch, an antibiotic could be released more continuously.”
Study in journal International Journal of Pharmaceutics: 3D printing of customized all-starch tablets with combined release kinetics