Customizable Self-Microemulsifying Rectal Suppositories by Semisolid Extrusion 3D Printing

Objectives: This study aims to create an innovative self-microemulsifying drug delivery system (SMEDDS) suppository for ibuprofen (IBU) using semisolid extrusion (SSE) three-dimensional (3D) printing technology. Methods: Based on solubility studies and the ability to form a transparent microemulsion upon dilution, a selected oil, surfactant, and co-surfactant were utilized to prepare SMEDDS-3DPS containing IBU. The optimal formulation consisted of 10% Triacetin, 80% Gelucire 48/16, and 10% Tetraethylene glycol. SSE 3D printing was employed to create three different-sized suppositories with varying drug contents. These suppositories were assessed for their physicochemical properties, content uniformity, and dissolution profiles. Results: The prepared mixture exhibited suitable physical properties for printing, with nano-sized emulsion droplets providing a large surface area for improved drug absorption in the rectum. Characterization techniques such as differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy indicated that IBU was present in the formulation in an amorphous state. Additionally, in vitro dissolution tests demonstrated that SMEDDS-3DPS had a significantly higher initial dissolution rate compared with IBU powder. Conclusions: This research suggests that SMEDDS-3DPS, as a rectal IBU dosage form, can enhance the rectal bioavailability of IBU. It demonstrates the versatility of 3D printing as a novel manufacturing method for lipid-based suppositories and highlights the simplicity and adaptability of SSE 3D printing technology in producing customized suppositories tailored to individual patient needs, surpassing traditional methods.