3D-Printing with precise layer-wise dose adjustments for paediatric use via pressure-assisted microsyringe printing.

The establishment of 3D-printing as manufacturing process for oral solid dosage forms enables new options for the individualized medicine. The aim of this work was to develop a novel drug-printing model using pressure-assisted microsyringe (PAM) technology, which allows the precise dispensing of drug substances. Printed tablets with different numbers of layers, mimicking different doses for pediatric subgroups, were analyzed regarding mass variation, friability, thickness and disintegration time. Furthermore, the uniformity of dosage units and the dissolution behavior were investigated. Friability was <0.3% in all cases, which demonstrates the ability of PAM printing to manufacture robust solid dosage. Disintegration results showed the dependency of the disintegration on the number of layers and therefore on the compact mass of polymer. However, all tablets disintegrated within 3 min and fulfilled the requirements of immediate release tablets of the USP and orodispersible tablets according to the Ph. Eur. Results of uniformity dosage units confirmed the successful manufacturing of the intended individualized doses. Drug dissolution appeared to be dependent on the number of layers. An increase of layers resulted in a decrease of the drug release rate. Further, the drug release could be correlated to the surface area/volume (SA/V) ratio.