Effect of flow conditions for the reproducible construction of colloidal drug carriers based on polycaprolactone

Flow chemistry allows for more precise control, lower cost, increased safety, improved efficiency, and thus higher reproducibility in chemical reactions. In this paper, the applicability of a commercially available microfluidic device (Syrris Asia Flow system (Syrris Ltd.)) was confirmed for the reproducible fabrication of both drug-free and drug-loaded colloidal particles composed of polycaprolactone (PCl). It was highlighted that tuning of the experimental parameters ( e.g ., flow rate, polymer concentration, and quality of stabilizers etc. ) greatly controls the size, structure, and encapsulation efficiency of the formed colloids. To the best of our knowledge, there is no similar publication in the literature, which would comprehensively characterize the effect of flow conditions and other experimental parameters on the production of these PCl particles. Colloids with a size of 210–300 nm were created in a flow system, and the effect of more than ten different stabilizers like polymers, surfactants, and proteins was evaluated on colloidal stability, encapsulation efficiency and drug release. UV-Vis spectrophotometry and differential scanning calorimetry studies confirm that 50–60% encapsulation efficiency (EE) and 18–25% drug loading (DL) can be achieved using Vitamin D3 as a model drug. Dissolution properties of D3 in model gastric juice medium (pH = 1.5) can be greatly controlled by the type of stabilizers in the range of 9–25%. The release curves were fitted by different kinetic model and the diffusion-controlled feature was obtained in every case. • Reproducible creation of polycaprolactone (PCl) colloids was proved by flow method. • Under flow conditions, hydrophobic vitamin D3 as a model drug was encapsulated. • The effect of various stabilizers on colloid stability was thoroughly interpreted. • The stabilizers greatly control the dissolution of the encapsulated drug.