Two-component cross-linkable gels for fabrication of solid oral dosage forms

Current three-dimensional (3D) printing techniques involve the solidification of the injected materials by means of UV irradiation, evaporation of organic solvents, or harsh heating and cooling processes. These methods limit the printing of many sensitive bio-active molecules such as proteins. We describe a novel 3D printing technique based on two complementary liquid copolymers, PEG₄-PCL-SC and PEG₄-PCL-NH₂, that are injected in a coordinated fashion and react with each other to form a pre-designed 3D pill. Printed pills swelled about 400% over 3 h, followed by moderate disintegration. Both prednisone and bovine serum albumin were incorporated into the printed pill, but while most of the prednisone was released depending on the ratio between the two complementary pre-polymers, only 40% of the bovine serum albumin was released from the pill. This unique 3D printing apparatus can be used to produce pills at home when the required medication does not handle current production techniques well and may have other possible biomedical applications. However, before this system can be considered for pharmaceutical applications, the low printing resolution, attributable to the slow gelation kinetics and the viscosity of the pre-polymers, should be addressed.