From API to Nano Drug Product – Part 1 | Beitrag aus pharmind 88 | Nr. 6 | Seite 470-474 (2026)

28.07.2026
This study investigates the integration of wet bead milling with fluid bed technologies, i.e. granulation and drug layering, respectively, as a combined method for developing stable oral nano drug products. Naproxen as Biopharmaceutical Classification System (BCS) Class II model active pharmaceutical ingredient (API) with low water solubility of 16 mg/L was nanomilled in the presence of suitable stabilizers (polymer and surfactant) using a wet bead milling system. The resulting nanosuspension was subsequently incorporated into carriers such as lactose, microcrystalline cellulose, and isomalt using top-spray and Wurster bottom-spray fluid bed processes. Note that the subsequent tableting or capsule/sachet filling process can be further developed if needed. The aim was to ensure the efficient incorporation of API nanocrystals into solid dosage forms while maintaining nanoparticle integrity and stability throughout the manufacturing process (part 1). The produced API nanoparticle-loaded granules and pellets were characterized by evaluating bulk and tapped density, particle size distribution (PSD), loss on drying, microscopy, and dissolution behavior. Specifically for nanoparticle formulations, redispersibility testing was performed, as it plays a critical role in defining Critical Quality Attributes (CQAs). The stability study was furthered under storage conditions of 25 °C / 60 % relative humidity (RH) (reported in Part 2).