Partial tablet coating by 3D printing.

In the last decade 3D printing (3DP) technology has gained increasing interest in the pharmaceutical field addressing several novel challenges such as on-demand manufacturing at the point of need, customization of drug release profiles and patient-specific solutions as well as combinations of several APIs in one dosage form. Therefore, 3DP can become a new and promising path to drug product development and manufacturing, able to support specific therapies and improve compliance, safety and effectiveness. The aim of this work was to partially coat tablets with a glyceride, namely Precirol ATO 5 using a semi-solids 3D printer as an approach for tuning the release of two Active Pharmaceutical Ingredients (APIs), the hydrophilic methyl-levodopa hydrochloride (Melevodopa) and the lipophilic Acyclovir. Various parameters of the 3DP coating process were purposefully modified using experimental design techniques in order to customize the selected APIs release profile, without affecting the core composition of the formulation. The percentage of the tablet surface coated, the number of coating layers as well as the coated sides of the tablet where the parameters which controlled the release profile for both APIs. Different dissolution profiles have been achieved by tuning these simple parameters, which revealed a non-Fickian release mechanism regardless of the API.

3D-liquid chromatography as a complex mixture characterization tool for knowledge-based downstream process development.

Knowledge-based development of chromatographic separation processes requires efficient techniques to determine the physicochemical properties of the product and the impurities to be removed. These characterization techniques are usually divided into approaches that determine molecular properties, such as charge, hydrophobicity and size, or molecular interactions with auxiliary materials, commonly in the form of adsorption isotherms. In this study we demonstrate the application of a three-dimensional liquid chromatography approach to a clarified cell homogenate containing a therapeutic enzyme. Each separation dimension determines a molecular property relevant to the chromatographic behavior of each component. Matching of the peaks across the different separation dimensions and against a high-resolution reference chromatogram allows to assign the determined parameters to pseudo-components, allowing to determine the most promising technique for the removal of each impurity. More detailed process design using mechanistic models requires isotherm parameters. For this purpose, the second dimension consists of multiple linear gradient separations on columns in a high-throughput screening compatible format, that allow regression of isotherm parameters with an average standard error of 8%. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1283-1291, 2016.