Internal liquid crystal structures in nanocarriers containing drug hydrophobic ion pairs dictate drug release

摘要

Hypothesis: Hydrophobic ion pairing (HIP), a solubility engineering technique in which ionic hydrophilic molecules are paired with a hydrophobic counterion, is an attractive strategy for encapsulating ionic water-soluble species into nanocarriers (NCs). Drug release from NCs containing HIP complexes is sensitive to ionic strength, pH, and drug:counterion charge ratio, but the exact mechanism for this was unknown, as was the underlying microstructure inside the NCs. We hypothesize that HIP complexes arrange into liquid crystalline structures in NC cores and that these structures are responsible for salt and pH-dependent release.