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Background/Objectives: Selective laser sintering (SLS) is one of the most promising 3D printing techniques for pharmaceutical applications as it offers numerous advantages, such as suitability to work with already approved pharmaceutical excipients, the elimination of solvents, and the ability to produce fast-dissolving, porous dosage forms with high drug loading. When the powder mixture is exposed to elevated temperatures during SLS printing, the active ingredients can be converted from the crystalline to the amorphous state, which can be used as a strategy to improve the dissolution rate and bioavailability of poorly soluble drugs. This study investigates the potential application of SLS 3D printing for the fabrication of tablets containing the poorly soluble drug carvedilol with the aim of improving the dissolution rate of the drug by forming an amorphous form through the printing process. Methods: Using SLS 3D printing, eight tablet formulations were produced using two different powder mixtures and four combinations of experimental conditions, followed by physicochemical characterization and dissolution testing. Results: Physicochemical characterization revealed that at least partial amorphization of carvedilol occurred during the printing process. Although variations in process parameters were minimal, higher temperatures in combination with lower laser speeds appeared to facilitate a greater degree of amorphization. Ultimately, the partial conversion to the amorphous form significantly improved the dissolution of carvedilol compared to its pure crystalline form. Conclusions: Obtained results suggest that the SLS 3D printing technique can be effectively used to convert poorly water-soluble drugs to their amorphous state, thereby improving solubility and bioavailability.

Various three-dimensional printing (3DP) technologies have been investigated so far in relation to their potential to produce customizable medicines and medical devices. The aim of this study was to examine the possibility of tailoring drug release rates from immediate to prolonged release by varying the tablet thickness and the drug loading, as well as to develop artificial neural network (ANN) predictive models for atomoxetine (ATH) release rate from DLP 3D-printed tablets. Photoreactive mixtures were comprised of poly(ethylene glycol) diacrylate (PEGDA) and poly(ethylene glycol) 400 in a constant ratio of 3:1, water, photoinitiator and ATH as a model drug whose content was varied from 5% to 20% (w/w). Designed 3D models of cylindrical shape tablets were of constant diameter, but different thickness. A series of tablets with doses ranging from 2.06 mg to 37.48 mg, exhibiting immediate- and modified-release profiles were successfully fabricated, confirming the potential of this technology in manufacturing dosage forms on demand, with the possibility to adjust the dose and release behavior by varying drug loading and dimensions of tablets. DSC (differential scanning calorimetry), XRPD (X-ray powder diffraction) and microscopic analysis showed that ATH remained in a crystalline form in tablets, while FTIR spectroscopy confirmed that no interactions occurred between ATH and polymers.

Three-dimensional (3D) printing technologies are based on successive material printing layer-by-layer and are considered suitable for the production of dosage forms customized for a patient’s needs. In this study, tablets of atomoxetine hydrochloride (ATH) have been successfully fabricated by a digital light processing (DLP) 3D printing technology. Initial materials were photoreactive suspensions, composed of poly(ethylene glycol) diacrylate 700 (PEGDA 700), poly(ethylene glycol) 400 (PEG 400), photoinitiator and suspended ATH. The amount of ATH was varied from 10.00 to 25.00% (w/w), and a range of doses from 12.21 to 40.07 mg has been achieved, indicating the possibility of personalized therapy. The rheological characteristics of all photoreactive suspensions were appropriate for the printing process, while the amount of the suspended particles in the photoreactive suspensions had an impact on the 3D printing process, as well as on mechanical and biopharmaceutical characteristics of tablets. Only the formulation with the highest content of ATH had significantly different tensile strength compared to other formulations. All tablets showed sustained drug release during at least the 8h. ATH crystals were observed with polarized light microscopy of photoreactive suspensions and the cross-sections of the tablets, while no interactions between ATH and polymers were detected by FT-IR spectroscopy.