Oral preparations with tunable dissolution behavior based on selective laser sintering technique.

Selective laser sintering (SLS) sinters a powder layer by layer with a laser beam to prepare 3D printlets, which are widely used in the field of tissue engineering and personalized implants. To promote the SLS printing of oral solid preparations, the printability of commonly used drugs and excipients was evaluated using a 450 nm low energy laser. It was found that yellow drugs could absorb laser energy and sinter, while white drugs and pharmaceutical excipients had SLS printability when tartrazine lake was added as a photoabsorber. The printing mechanism of non-crystalline and crystalline polymers was powder sintering and powder melting, respectively. Increasing the laser energy density was beneficial to the printing efficiency but reduced printing accuracy. To ensure the integrity of multilayer printlets, the sintered thickness of each layer should be greater than the layer thickness. Furthermore, ibuprofen immediate-release tablets and metoprolol tartrate sustained-release tablets were prepared. Using 10% carboxy methyl starch sodium as an additive, the shell tablets with a side thickness of 1.5 mm had a good appearance and fast dissolution. Based on the optimized formulation, IBU preparations with various design shown good appearance and fast release property. There was no difference in the drug's crystalline state after SLS printing. Besides, the printed reservoir tablets with a sustained-released coating thickness of 3.5 mm had a good appearance and allowed 12 h sustained release. The results revealed that the SLS technique has great prospects in producing personalized oral preparations with immediate-release and sustained-release properties.