PSI - Issue 82

Krastena Nikolova et al. / Procedia Structural Integrity 82 (2026) 227–233 K. Nikolova et al./ Structural Integrity Procedia 00 (2026) 000–000

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drug delivery systems (SNEDDS) have been directly printed into solid tablets using PAM-based 3D printing. These lipid systems consist of a liquid phase (oils and surfactants) and a solid phase (the drug-loaded matrix). After melting the excipients, the formulation was loaded into the cartridge of a 3D printer and extruded via PAM. Using this approach, a SNEDDS-loaded dapagliflozin tablet was produced, achieving >75% drug release within 20 minutes (Barber B.W. et al. 2021). A similar methodology has also been applied in the fabrication of 3D-printed suppositories loaded with lidocaine for the treatment of hemorrhoids (Algahtani M. et al. 2021). 2.4. Semi-solid dosage forms for topical administration The development of wound dressings for application to the skin, aimed at accelerating wound healing, represents one of the emerging applications of 3D printing. Pressure-assisted microsyringe (PAM) is a promising 3D technology that employs bioinks composed of gelatin methacryloyl (GelMA) and xanthan gum, which demonstrate excellent printability (Van Kogelenberg S. et al. 2018). Another frequently used bioink component, due to its low cost combined with biodegradability and biocompatibility, is the polysaccharide chitosan (Yang Z. et al. 2021). Using 3D printing, hydrogels based on chitosan and pectin containing lidocaine have been developed (Lazaridou M. et al. 2022). These systems provide effective absorption of the active substance, maintain adequate skin moisture around the wound site, and exert a local anesthetic effect. Another interesting application is the 3D printing of microneedles fabricated by stereolithography (SLA). The printed solid microneedle structure is typically prepared from commercial resins and subsequently coated with cisplatin (Muwaffak Z. et al. 2017). Such devices have been applied in the treatment of skin tumors. Similar approaches have been used for the development of microneedle systems for insulin delivery. In these designs, a tricomponent insulin structure is applied onto the solid microneedle using specialized inkjet printing With the advent of 3D printing, there has been increasing interest in the development of localized drug delivery systems, which reduce the adverse effects of pharmaceutical formulations by minimizing drug exposure to healthy tissues (Bloomquist C.J. et al. 2018). Such locally extended-release systems are frequently applied in procedures requiring intraocular injections, which otherwise carry the risk of elevated intraocular pressure (Al-Kinani A.A. et al. 2018). Drug-eluting implants have found applications in contraception, cardiovascular diseases, ocular disorders, peritoneal delivery, and other therapeutic areas (Szabo P. et al. 2015). It has been demonstrated that fused deposition modeling (FDM) can be used to print drug-loaded filaments. Fu et al. employed FDM to produce progesterone vaginal rings with controlled release of the hormone (Fu J. et al. 2018).Another frequently investigated formulation is the “matryoshka-type” suppository, consisting of multilayered shells containing different active ingredients (Tagami T. et al. 2019). In addition, personalized catheters incorporating gentamicin have been developed using FDM technology (Weisman J.A. et al. 2019). 4.Conclusion 3D printing is increasingly finding applications in pharmaceutical technology. It enables the creation of adapted and personalized medicinal products tailored to the needs of individual patients. The technology allows the combination of multiple drugs into a single dosage form, thereby facilitating patient compliance, as well as the development of child-friendly formulations that improve swallowability. Moreover, it offers the possibility of fabricating wound dressings customized to the characteristics of a patient’s wound, as well as microneedles for transdermal drug delivery into deeper layers of the skin. In addition to these opportunities, such as the development of microfluidic chips and the 3D printing of biopharmaceuticals, this technology also faces several challenges, including: the creation of novel 3D-printed tablets designed for specific pathologies for which no commercial medicinal product currently exists; the lack of clear regulatory guidelines for the manufacturing of such dosage forms, as well as limited availability of trained personnel; The limited access to GMP-compliant 3D printers, which are essential to prevent cross-contamination. This is particularly problematic with FDM printers, where different formulations pass through the same extrusion nozzle, (Elahpour N. et al. 2021). 3. Drug-Eluting Devices