Selective laser sintering additive manufacturing of solid oral dosage form: Effect of laser power and hatch spacing on the physico-technical behaviour of sintered printlets

Selective laser sintering is a laser-based powder bed fusion 3D printing technique in which, the laser parameters plays a vital role in the fusion of polymeric powder particles and the behavior of the final printed object. Hence, the objective of the current study was to investigate the impact of laser power and hatch spacing on the fusion of particles, followed by their physicochemical and mechanical behavior investigations of the final sintered object made with dapsone and poly (1-vinylpyrrolidone-co-vinyl acetate) as a model drug and polymer, respectively. An increase in laser power and a decrease in hatch spacing improved particle fusion, resulting in smoother surface, increased density, and better mechanical properties. Interestingly, there was a loss of drug crystallinity was experienced in respect to varied laser parameters, highlighting the potential of laser-based powder bed fusion technique in developing amorphous solid dispersions. Despite extensive laser parameters, drug entrapment efficiency was found to be greater than 90 % for all sintered batches. No notable differences were observed in the dissolution behavior of all performed samples although it was anticipated to achieve as there was differences witnessed in porosity and disintegration time. Finally, the oral pharmacokinetics study revealed the comparable performance of the sintered dosage form with the tablet prepared with conventional direct compression techniques. Overall, these findings demonstrate that with varying laser parameters, various properties of the final sintered object can be manipulated which further showed the flexibility of this 3D printing technique to fabricate dosage form with a more personalized and customized needs.