3D printing of unique water-soluble polymer-based suppository shell for controlled drug release.

3D printing technology holds promise for application to personalized pharmaceuticals. Mold fabrication is a common technique in industrial 3D printing to produce objects with complex structures and could be used in new applications in pharmaceutical production. The aim of the current study is the fabrication of unique suppository shell molds composed of a water-soluble polymer (polyvinylalcohol) using a fused deposition modeling-type 3D printer so that hospital pharmacists can prepare tailored suppository formulations containing progesterone (a model drug for vaginal suppository formulations) in future clinical settings. Suppository formulations with holes in the shells were prepared. The drug release profiles related well to the positions of the holes (upper, middle, lower), the number of holes (0-2 holes), and the diameters of the holes (0-5 mm) in the suppositories. Matryoshka-type suppository formulations composed of 3D-printed multilayered shells were then prepared. The drug release profiles showed pulsed release, and the volumes of the inner/outer spaces in the suppository shells (1/1, 1/3) and the drug concentration (3/1, 1/1) were reflected in the observed drug release profiles. Our study indicates that a 3D printer can produce not only unique and complex suppository formulations, but also provides flexibility and expands possible applications for the development of tailored medicine.