For the purpose of personalized therapies, the Materials + Technologies (GMT) group of the UPV/EHU used 3D printing to develop tablets based on different types of starch, and confirmed that drug delivery could be tailored by optimizing the right type of starch and tablet shape.
Traditional methods produce drugs with specific parameters, but in many cases do not meet the individual needs of patients. In fact, conventional medications tend to be based on adult doses, so pediatric and elderly patients need age-appropriate doses. Additionally, some patient groups also require specific dosage form alternatives to facilitate oral drug delivery. In this regard, fast disintegrating tablets appear to be a good option because they dissolve the moment they are placed on the tongue. Another challenge faced by pharmaceutical laboratories is the controlled release of the drug over time, in particular when the drug is of the hydrophobic type, that is to say when its dissolution in water poses problems.
In this context, “3D printing technology is an advanced technique for personalized medicine and the development of on-demand drug release tablets,” said Kizkitza González of the Materials+Technologies (GMT) group at UPV/ EHU. “The primary goal of this work was to produce 3D-printed starch-based tablets for the tailored delivery of hydrophobic drugs,” the paper’s author said.
3D printing is a technology that involves printing products layer by layer, in which the materials are deposited according to the digital model designed by computer design software. Following a simple and fast methodology and thanks to 3D printing, “we were able to prepare tablets based on three types of starch – two types of corn starch (normal and waxy) and one type of apple starch. earth- of different geometries and loaded with an insoluble drug,” said Kizkitza González.
Corn and potato starch
“The material produced must be inserted into a syringe before printing. However, before that, it must be ensured that the material is going to be printable and that once printed, it will keep its shape. To do this, a rheological analysis detail has to be made,” explains the UPV/EHU researcher. All three types of starch showed suitable rheological properties, although in the case of potato starch the printing process proved to be more laborious in because of its properties.
Moreover, “we observed the importance of the botanical origin of starch in practically all properties, such as the porous microstructure, the formation of a stable network or the release of the drug. In the case of normal corn starch, the release of the drug is instantaneous and the drug is fully released within 10 minutes; in the case of waxy corn starch and potato starch, the release is more continuous and can take up to 6 hours for complete release. We were also able to demonstrate the importance of tablet geometry in drug release,” said Kizkitza González.
Finally, “tablets combining different types of starch have also been printed. In this case, the release takes place in two stages. For example, in the event of an infection, in a first step using normal cornstarch, a drug could be released immediately to relieve pain, and in a later step, with either of the other two types of starch, an antibiotic could be released more continuously,” said the UPV/EHU researcher.
Kizkitza González is aware that this work is only the first step in a long process, but she maintains that “the starch-based 3D-printed tablets they produced showed promising properties for future applications in ‘personalized drug delivery’.