It can be tricky to take exactly one fourths of a pill or the specific dose of prescribed medication, which is why researchers at Purdue University have come up with a way to print the proper dosage that a patient requires. Their prototype uses inkjet printing technology and a predictive mathematical model that calculates exactly how much medicine the patients needs and prints out the precise doses into tablets or films.

Though we've seen printable prescription pills, it's also important to take the right amount of the medication as it has an impact on how a drug affects the body. Most people try to adjust the dose themselves through trial and error, but this could have unexpected side effects.

"Pharmaceutical companies make one or two or three dosage levels, so people try breaking tablets in half and other methods to get to the right dosage," says Professor Gintaras Reklaitis, Purdue University. "Many drugs have a minimum effective level, so you need to meet that, and many of them have a toxic level. The closer you get to it the more side effects there are."

The Purdue prototype uses mathematical models and blood sampling to determine the exact amount of medicine a person needs. The technique involves taking two or three blood samples from a patient who has been given a small amount of the medicine.

The blood sample information, along with data from clinical studies, is analyzed and is used in combination with mathematical models to determine the correct dose. Once that's done, a portable system melts or dissolves the drugs into polymers, and produces very precise doses using "drop-on-demand" inkjet printing technology.

"If we say the patient needs 23 milligrams every eight hours, there is no 23-milligram tablet on the market," Purdue researcher Arun Giridharsays. "I can make a 23-milligram dose, but to make something that small and that precise is challenging to do with powders. It is much easier to dissolve or melt the drug formulation. Both are viable technologies."

Additionally, melting medications this way could allow manufacturers to create more blood-soluble drugs, the scientists claim, as it's possible to have more precise control the drug's properties.

"We envision that in its final form the printing will be done in an automated fashion," says Reklaitis. "The pharmacist could key in the dose, the machine prints 20 tablets, and off you go."

The researchers say that monitoring the drug's effectiveness over time also becomes easier with this procedure, as it allows medical staff to observe its effects and change doses as needed. The effectiveness of the procedure is currently being evaluated in clinical studies, with a view to commercializing the prototype.

The research was published earlier this year in the Journal of Pharmaceutical Sciences