Solution Coating of Pharmaceutical Nanothin Films and Multilayer Nanocomposites with Controlled Morphology and Polymorphism
mediaposted on 08.03.2018, 00:00 by Elizabeth M. Horstman, Prapti Kafle, Fengjiao Zhang, Yifu Zhang, Paul J. A. Kenis, Ying Diao
Nanosizing is rapidly emerging as an alternative approach to enhance solubility and thus the bioavailability of poorly aqueous soluble active pharmaceutical ingredients (APIs). Although numerous techniques have been developed to perform nanosizing of API crystals, precise control and modulation of their size in an energy and material efficient manner remains challenging. In this study, we present meniscus-guided solution coating as a new technique to produce pharmaceutical thin films of nanoscale thickness with controlled morphology. We demonstrate control of aspirin film thickness over more than 2 orders of magnitude, from 30 nm to 1.5 μm. By varying simple process parameters such as the coating speed and the solution concentration, the aspirin film morphology can also be modulated by accessing different coating regimes, namely the evaporation regime and the Landau–Levich regime. Using ellipticinea poorly water-soluble anticancer drugas another model compound, we discovered a new polymorph kinetically trapped during solution coating. Furthermore, the polymorphic outcome can be controlled by varying coating conditions. We further performed layer-by-layer coating of multilayer nanocomposites, with alternating thin films of ellipticine and a biocompatible polymer, which demonstrate the potential of additive manufacturing of multidrug-personalized dosage forms using this approach.
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solution Coating1.5 μ mAPI crystalsaspirin film morphologycoating regimescoating speedsolution concentration2 orderspolymorphic outcomelayer-by-layer coatingmultidrug-personalized dosage formsprocess parametersevaporation regimePharmaceutical Nanothin Films30 nmcoating conditionsaspirin film thicknessPolymorphism Nanosizingpolymorph kineticallyalternative approachnanoscale thicknessControlled MorphologyMultilayer Nanocompositesmeniscus-guided solution coatingbiocompatible polymermodel compoundadditive manufacturingsolution coating