Abstract

Conventional immediate release dosage forms involve compressing the powder with a disintegrating agent that
enables rapid disintegration and dissolution upon oral ingestion. Among 3D printing technologies, the fused
deposition modelling (FDM) 3D printing technique has considerable potential for patient-speciTc dosage form.
However, the use of FDM 3D printing in tablet manufacturing requires large portion of polymer, which slows
down drug release through erosion and diffusion mechanisms. In this study, we demonstrate for the Trst time
the use of a novel design approach of caplets with perforating channels to accelerate drug release from 3D
printed tablets. This strategy has been implemented using a caplet design with perforating channels of increasing
width (0.2, 0.4, 0.6, 0.8 or 1.0 mm) and variable length, and alignment (parallel or at right angle to tablet
long axis). Hydrochlorothiazide (BCS class IV drug) was chosen as model drug as enhanced dissolution rate is
vital to guarantee oral bioavailability. The inclusion of channels exhibited an increase in the surface are/volume
ratio, however, the release pattern was also inUuenced by the width and the length of the channel. A channel
width 0.6 mm deemed critical to meet the USP criteria of immediate release products. Shorter multiple channels
(8.6 mm) were more efTcient at accelerating drug release than longer channels (18.2 mm) despite having
comparable surface area/mass ratio. This behaviour may be linked to the reduced Uow resistance within the
channels and the faster fragmentation during dissolution of these tablets. In conclusion, the width and length of
the channel should be carefully considered in addition to surface area/mass when optimizing drug release from
3D printed designs. The incorporation of short channels can be adopted in the designs of dosage forms, implants
or stents to enhance the release rate of eluting drug from rich polymeric structures.