Self-assembling properties of ionisable amphiphilic drugs in aqueous solution

Hypothesis: Common amphiphilic drug molecules often have a more rigid nonpolar part than conventional surfactants. The rigidity is expected to influence the self-assembling properties and possibly give rise aggregation patterns different from that of regular Experiments: We investigated hydrochloride salts adiphenine (ADP), pavatrine (PVT), amitriptyline (AMT) at concentrations up 50 wt% using small-angle x-ray scattering, dynamic light cryo-transmission electron microscopy, surface tension measurements. Findings: All drugs form small micelles oblate spheroidal shape above critical micelle (CMC). grow weakly in size about 20 wt%, where number reaches maximum followed by slight decrease higher concentrations. observe correlation between high an increasing charge micelles, as degree ionization increases with concentration decreasing pH. In contrast what has previously been reported, behavior all studied resembles closed association surfactants short aliphatic chain hydrophobic tail group i.e. are always lack second CMC. CMC values were determined measurements, including also lidocaine (LDC) chlorpromazine (CHL).