A New Approach to Manufacturing Oral Drug Delivery Systems via Selective Laser Sintering with Water-Insoluble Biocompatible Thermoplastic Polymers: Gaps, Risks, Challenges, and Future Directions

Selective Laser Sintering (SLS), a laser-based powder bed fusion additive manufacturing technique, has emerged as a promising platform for the fabrication of individualized pharmaceutical dosage forms. This review provides a comprehensive analysis of the usefulness of biocompatible thermoplastic polymers - specifically polyamide 12 (PA12) and polyethylene (PE) - with regards to their physicochemical properties, printability, and functional performance in drug delivery applications. The suitability of these polymers for SLS is assessed in the context of their thermal behavior, structural integrity, and ability to modulate drug release profiles. Emphasis is placed on the toxicological implications of SLS processing, including the formation of volatile organic compounds (VOCs), thermal degradation byproducts, and the generation of micro- and nanoplastics (MNPs), which may pose significant occupational and patient health risks upon inhalation or ingestion. Despite growing interest in SLS-based pharmaceutical manufacturing, critical knowledge gaps regarding the long-term biological fate of these materials, especially under high-energy processing conditions, still persist. The review highlights current regulatory limitations, the absence of standardized pharmacopeial assays, and the challenges associated with powder reuse, sinterability assessment, and emission control. To ensure the safe clinical translation of SLS-fabricated pharmaceuticals, a multidisciplinary approach encompassing material science, toxicology, process engineering, and regulatory science is essential.