Fabricating 3D printed orally disintegrating printlets
Selective laser sintering (SLS) is a three-dimensional printing (3DP) technology employed to manufacture plastic, metallic or ceramic objects. The aim of this study was to demonstrate the feasibility of SLS to fabricating novel solid dosage forms with accelerated drug release properties, and with a view to create orally disintegrating formulations. Two polymers (hydroxypropyl methylcellulose (HPMC E5) and vinylpyrrolidone-vinyl acetate copolymer (Kollidon® VA 64)) were separately mixed with 5% paracetamol (used as a model drug) and 3% Candurin® gold sheen colorant; the powder mixes were subjected to SLS printing resulting in the manufacture of printlets (3DP tablets). Modulating the SLS printing parameters altered the release characteristics of the printlets, with faster laser scanning speeds accelerating drug release from the HPMC formulations. The same trend was observed for the Kollidon® based printlets. At a laser scanning speed of 300 mm/s, the Kollidon® printlets exhibited orally disintegrating characteristics by completely dispersing in less than 4 seconds in a small volume of water. X-ray micro-CT analysis of these printlets indicated a reduction in their density and an increase in open porosity, therefore, confirming the unique disintegration behaviour of these formulations. The work reported here is the first to demonstrate the feasibility of SLS 3DP to fabricate printlets with accelerated drug release and orally disintegrating properties. This investigation has confirmed that SLS is amenable to the pharmaceutical research of modern medicine manufacture.
Printlets with different drug release properties have been manufactured by modulating the laser scanning speed of an SLS 3D printer. The versatility of the SLS technology was demonstrated by drastically accelerating the drug dissolution profiles of printlets prepared with two pharmaceutical grade polymers that have not been explored previously with SLS 3DP. Kollidon based printlets, prepared using a less energetic sintering process at a laser scanning speed of 300 mm/s, disintegrated within 4 seconds in a small volume of water. This work reports for the first time the successful manufacture of orally disintegrating printlets using SLS 3D printing.