The impact of applying an additional polymer coating on high drug-loaded amorphous solid dispersions layered onto pellets

Enteric coating of tablets containing an amorphous solid dispersion of an enteric polymer and a weakly basic drug: A strategy to enhance in vitro release

“…ASDs of niclosamide with copovidone (60% DL) exhibited crystallization in a simulated gastric medium (pH 2.0) after immersion for 30 min which could be circumvented by formulating as enteric-coated tablets which delayed drug release until the higher pH environment of the intestine, where crystallization was less favorable due to ionization of the drug ( Jara et al, 2022 ). Non-enteric coatings have also been used to reduce amorphous drug crystallization during storage of the solid formulation ( Boel and Van den Mooter, 2023 , Li et al, 2019 , Zeng et al, 2019 ). Polymer nanocoating via electrostatic interactions between drug and polymer was applied to improve the stability of amorphous weakly basic drugs, including loratadine ( Zeng et al, 2019 ); clofazimine ( Gui et al, 2019 , Gui et al, 2021 ); or a weakly acidic drug, indomethacin ( Li et al, 2019 ).…”

“…Polymer nanocoating via electrostatic interactions between drug and polymer was applied to improve the stability of amorphous weakly basic drugs, including loratadine ( Zeng et al, 2019 ); clofazimine ( Gui et al, 2019 , Gui et al, 2021 ); or a weakly acidic drug, indomethacin ( Li et al, 2019 ). Drug crystallization during storage of high drug loading naproxen-copovidone ASDs was inhibited by applying an additional coating of ethyl cellulose ( Boel and Van den Mooter, 2023 ). More recently, atomic layer coating has attracted attention as an effective surface crystallization inhibitor of high drug loading ASDs of fast crystallizers ( Moseson et al, 2022a , Moseson et al, 2022b , Van Duong et al, 2022b ).…”