Fused deposition modelling is a three-dimensional printing process. It represents an
innovative way of manufacturing personalised oral dosage forms. By altering their shape, the
constitution of their formulations and their infill percentages, we can modify their release.
This is possible, as fused deposition modelling creates tablets composed of layers of grids,
that enable high levels of porosity and in many cases also immediate release.
We evaluated the key factors that impact the tablets quality and stability. These tablets were
ketoprofen-based and were developed from 17 sorts of filaments that have been developed.
They were composed of one or two polymers, mannitol and silicon dioxide. The infill
percentage of the printed tablets was 50%. The filaments were created with holt melt extrusion
and then inserted into the three-dimensional printer. We first measured the dimensions of the
printed tablets and then proceeded with dissolution studies. This was followed by
disintegration studies and purity profile determination. We selected the formulation with the
fastest and slowest dissolution rate and used them for the creation of a single tablet, that
combined both types of modified release. We then proceeded to the second phase in which
we designed tablets with altered shapes. These tablets had holes built in their structure which
enhanced the surface to volume ratio. We also designed tablets with a 20 and 80 infill
percentage. This was done so we could evaluate the impact of tablet shapes and infill
percentages on the dissolution rate. We then concluded our studies with phase three in which
we exposed a sample of tablets made out of each formulation to a temperature of 40°C and
75% relative humidity for 3 months. This was followed by a dissolution test and a HPLC
analysis of impurities that have developed. Out of all 17 formulations, we chose the ones that
do not exhibit impurity levels and dimension deviations that exceed specification. 6 out of 17
were deemed suitable. 3 out of 17 formulations caused tablet deformation after 3 months due
to lowered glass transition temperatures, which was caused by water absorption 4 out of 17
formulations contained too much impurities after 3 months. 4 out of 17 formulations caused
excessive dimension deviations. 2 formulations were developed into regular shaped tablets
with immediate release at 50% infill.
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