Solubility and loading ability of benzene derivative drugs onto viscose substrate in supercritical carbon dioxide and their release behavior in solvent

An investigation of the solubility and loading ability (LA) of nine benzene derivative drugs with different chemical structures onto viscose substrate in supercritical carbon dioxide fluid (SCF–CO2) was performed, in order to construct some bases at the first time for manufacturing drug-loaded cosmetic textiles by employing an ecofriendly, sustainable supercritical methodology. Moreover, a release behavior of each of the loaded drugs from viscose substrate in a solvent of ethanol was also disclosed. The results show that a more hydrophobicity of the substituent group linked on the benzene ring readily led to a higher solubility in SCF-CO2, while an overlong aliphatic tail and its molar mass also brought some effects on its dissolving behavior. As for the isomer drugs, the locations of a methoxy group (-O-CH3) at the ortho-position to the carboxyl group (-(CO)–OH) in the benzene ring resulted in the highest solubility, while a para-position showed the lowest solubility in SCF-CO2. The loading ability (LA) for most of the tested drugs mainly depended on their solubilities in SCF-CO2, and was also affected by the interactions between the drug and viscose substrate. The investigation of drug release reveals that the LA played a predominant role in the release behaviors of the tested drugs with different substituent groups, molar mass or aliphatic chains and isomer structures. Moreover, the drug molecular size and its interaction with viscose substrate also presented effects on the subsequent release behaviors in the utilized release system and conditions.