Table 2.

Representative pharmaceutical application of 3D printed oral/vaginal/rectal drug delivery.

	3D Printing Strategy	Achievement	Reference
Oral drug delivery system	Piezoelectric inkjet printing with drug dissolved in propylene glycol	Automated engineering of medicines; precise patterning of porous substrates and dosing of low-dose drug substances	[189]
	Piezoelectric inkjet printing with drug mixed in pre-polymer solution	Immediate drug release profile owing to hydrophilic active materials for accurate dosing	[190]
	Extrusion-based printing with drug loaded filament	Coated with a layer of enteric polymer to prevent drug degradation in acidic pH	[183]
	Dual extrusion-based 3D printing	Core-shell designs for delayed-release kinetics; drug with high water solubility and gastric-resistant products	[37]
	Extrusion-based 3D printing	Five-in-one dose combination polypill with controlled release	[46]
	STL with drug mixed in pre-polymer	Torus-shaped drug carrier for customized drug release profile	[184]
Vaginal/rectal drug delivery system	Extrusion-based 3D printing with estrogen and/or progesterone	Personalized implants and devices for obstetric and gynecological applications.	[191]
	Extrusion-based 3D printing with drug mixed in pre-polymer	Custom-made T-shaped intrauterine systems and subcutaneous rods	[192]
	STL with drugs mixed in pre-polymer	Non-dissolving suppository/pessary with tunable and sustained drug release	[186]