Optimizing Intestinal Drug Delivery: A Comparative Study of Commercial Enteric Capsules and 3D-Printed Capsules with...

Conventional gelatin capsules deliver a rapid drug release in the stomach, which is suboptimal for therapies requiring controlled and delayed release, emphasizing the need for customizable drug delivery systems for precision medicine. This study's objective was to optimize 3D-printed capsule shells formulated with pH-responsive polymer blends-hydroxypropyl methylcellulose acetate succinate (HPMC-AS), PEG-4000, and PVA-to achieve controlled and sustained drug release, comparing profiles against a commercial enteric capsule. Capsule shells were produced via fused filament fabrication (FFF) at two ratios (80:15:5 and 70:20:10), filled with acetaminophen (250 mg), and tested using a two-stage dissolution method (simulated gastric fluid (SGF) for 2 h followed by simulated intestinal fluid (SIF) for 4-5 h). Results showed negligible drug release in SGF (≤5%) for both printed and commercial capsules. However, in SIF, the commercial capsule released its payload rapidly (>80% within 15 min), while the 3D-printed capsules achieved a prolonged, gradual release. The higher HPMC-AS content significantly extended the release duration. All capsules met the pharmacopeial weight uniformity criteria. In conclusion, the 3D-printed shells provided a controllable, sustained drug release profile, underscoring 3D printing's potential to create tunable, patient-specific dosage forms.