The aims of this work were to develop a processable, electrospun formulation of a model biopharmaceutical drug, β-galactosidase, and to demonstrate that higher production rates of biopharmaceutical-containing fibers can be achieved by using high-speed electrospinning compared to traditional electrospinning techniques. An aqueous solution of 7.6 w/w% polyvinyl alcohol, 0.6 w/w% polyethylene oxide, 9.9 w/w% mannitol, and 5.4 w/w% β-galactosidase was successfully electrospun with a 30 mL/h feeding rate, which is about 30 times higher than the feeding rate usually attained with single-needle electrospinning. According to X-ray diffraction measurements, polyvinyl alcohol, polyethylene oxide, and β-galactosidase were in an amorphous state in the fibers, whereas mannitol was crystalline (δ-polymorph). The presence of crystalline mannitol and the low water content enabled appropriate grinding of the fibrous sample without secondary drying. The ground powder was mixed with excipients commonly used during the preparation of pharmaceutical tablets and was successfully compressed into tablets. β-galactosidase remained stable during each of the processing steps (electrospinning, grinding, and tableting) and after one year of storage at room temperature in the tablets. The obtained results demonstrate that high-speed electrospinning is a viable alternative to traditional biopharmaceutical drying methods, especially for heat sensitive molecules, and tablet formulation is achievable from the electrospun material prepared this way.

Electrospinning is a technology for manufacture of nano- and micro-sized fibers, which can enhance the dissolution properties of poorly water-soluble drugs. Tableting of electrospun fibers have been demonstrated in several studies, however, continuous manufacturing of tablets have not been realized yet. This research presents the first integrated continuous processing of milled drug-loaded electrospun materials to tablet form supplemented by process analytical tools for monitoring the active pharmaceutical ingredient (API) content. Electrospun fibers of an amorphous solid dispersion (ASD) of itraconazole and poly(vinylpyrrolidone-co-vinyl acetate) were produced using high speed electrospinning and afterwards milled. The milled fibers with an average fiber diameter of 1.6 ± 0.9 µm were continuously fed with a vibratory feeder into a twin-screw blender, which was integrated with a tableting machine to prepare tablets with ~ 10 kN compression force. The blend of fibers and excipients leaving the continuous blender was characterized with a bulk density of 0.43 g/cm³ and proved to be suitable for direct tablet compression. The ASD content, and thus the API content was determined in-line before tableting and at-line after tableting using near-infrared and Raman spectroscopy. The prepared tablets fulfilled the USP content uniformity requirement based on the API content of ten randomly selected tablets. This work highlights that combining the advantages of electrospinning (e.g. less solvent, fast and gentle drying, low energy consumption, and amorphous products with high specific surface area) and the continuous technologies opens a new and effective way in the field of manufacturing of the poorly water-soluble APIs.

Tablet film coating is governed by three interrelated phenomena, namely, tablet mixing, coating-liquid spraying, and liquid evaporation, which dominate the critical quality attributes ($CQAs$) of the final product. This review examines how differences in coater design, key process parameters, and quality control strategies impact these phenomena and ultimately affect inter-tablet and intra-tablet coating variability. Two complementary approaches for understanding and optimizing the process are evaluated. The experimental approach, involving Design of Experiments (DoE), retrospective data analysis, and advanced Process Analytical Technology ($PAT$), provides empirical insight into factor–response relationships and enables real-time quality assurance. Simultaneously, model-based approaches, including thermodynamic, spray-dynamics, and particle-dynamics modelling, offer mechanistic understanding of heat and mass transfer, droplet deposition patterns, and tablet motion. Although these sub-models have advanced considerably over the years, a predictive model that treats the coating process in its entirety is still missing. Overall, this review underscores that future advancements will require integrating experimental and model-based methodologies to achieve robust, quality-driven, and predictive control of tablet film coating processes.