Stereolithography (SLA) 3D printing of ascorbic acid loaded hydrogels: A controlled release study.

Patients' genetic characteristics, age, gender, diet, and lifestyle affect the success of medical treatment. The treatment's effectiveness can be increased by using personalized medication; however, using conventional large-scale drug production methods can restrict tablet geometry and drug dosage combinations. To create these personalized drugs, 3D printing has been studied as an alternative production method. In this study, stereolithography 3D printing is used to create custom tablet geometries using a novel biocompatible photochemistry consisting of ascorbic acid (AA) encapsulated in a poly(ethylene glycol) dimethacrylate (PEGDMA)-based polymer network and polymerized using riboflavin as a photoinitiator. The printing process is customized for the chemistry and different geometries (small and large tablet, coaxial annulus, 4-circle pattern and honeycomb pattern) with surface area to volume ratios ranging from 0.6 to 1.83 are fabricated. The tablets' microstructures are examined and the cumulative release rates in gastrointestinal conditions are analyzed periodically for 6 h. After 1 h of release, honeycomb and coaxial annulus tablet gels exhibit higher release rates at approximately 80%. The experimental data is fitted to empirical release kinetic models and the Higuchi model is shown to yield the best fitting results. Overall, by using a novel biocompatible photochemistry and 3D printing we have shown that it is possible to successfully load and release ascorbic acid as a model agent, opening up a new class of manufacturing protocols to encapsulate ascorbic acid and other water-soluble vitamins as well as many different drugs for drug delivery applications.