Impact of critical process parameters on the dimensional, mean weight, and swelling properties of 3D-printed intravaginal rings: a quality by design approach

3D printing is emerging as a transformative technology in pharmaceutical manufacturing, enabling personalized medicine and innovative dosage forms. It allows precise control over drug release and dosage customization, addressing individual patient needs. Various 3D printing techniques, including fused deposition modeling (FDM), are being explored for pharmaceutical applications. The choice of polymers and their rheological properties is crucial for successful extrusion-based printing. While 3D printing accelerates drug development, challenges remain regarding quality control. Quality-by-design (QbD) approaches are essential to ensure safe and effective pharmaceutical products. This study highlights the role of critical process parameters (CPPs), such as infill density and printing speed, in producing poly(lactic acid)-based intravaginal rings. The effects of CPPs on critical quality attributes (CQAs), such as ring dimensions, weight, and swelling degree, were examined. Printing speed (25-100 mm/s) and infill density (0-20%) significantly affected weight and dimensions, with average weights ranging from 0.537 g to 0.629 g. Internal dimensions varied between 9.73 mm and 9.81 mm, while external dimensions ranged from 19.43 mm to 19.69 mm. Rings printed at the lowest speed and highest infill density showed the greatest swelling (2.47%). These findings confirm FDM as a viable method for producing cost-effective, patient-specific intravaginal rings with reproducible results.