A Proof of Concept for 3D Printing of Solid Lipid-Based Formulations of Poorly Water-Soluble Drugs to Control Formulation Dispersion Kinetics

Purpose: The use of three-dimensional printing (3DP) in the development of pharmaceutical dosage forms is growing rapidly. However, the research is almost exclusively focussed on polymer-based systems with very little reported on 3D printing of lipid-based formulations. Thus, the aim of the work was to explore the feasibility of 3DP technology to prepare solid lipid-based formulations. Here, 3DP was applied for the preparation of solid self-microemulsifying drug delivery systems (S-SMEDDS) with defined surface area to volume (SA/V) ratios. 

Methods: The S-SMEDDS formulations, comprised of Gelucire® 44/14, Gelucire® 48/16 and Kolliphor® P 188 were loaded with fenofibrate or cinnarizine as model drugs. The formulations were printed into four geometrical shapes - cylindrical, prism, cube and torus, and compared to a control cube manually prepared from bulk formulation. 

Results: The printing process was not significantly affected by the presence of the model drugs. The as-printed S-SMEDDS formulations were characterised using differential scanning calorimetry and wide-angle X-ray scattering. The kinetics of dispersion depended on the SA/V ratio values. The digestion process was affected by the initial geometry of the dosage form by virtue of the kinetics of dispersion of the dosage forms into the digestion medium. 

Conclusions: This proof of concept study has demonstrated the potential of 3DP for the development of customised S-SMEDDS formulations without the need for an additional carrier or additive and with optimisation could elaborate a new class of dosage forms based on 3D printed lipids.