Amphotericin B microparticles ‘AmbiShell’ from phospholipid and gelatin: Development and investigation by combined DLS and SANS resolves the core‐shell structure

Abstract

A novel homogenous core‐shell formulation ‘AmbiShell’ of the hydrophobic antifungal polyene drug Amphotericin B was prepared from the pure drug, lecithin, and gelatin. The established ‘Hydrophilic Solubilisation Technology’ (HST) was used for embedding the lipophilic drug with lecithin and gelatin, yielding core‐shell microparticles of 1 µm size. The particle size of the drug, the formulation, and the thickness of the coating were investigated by using dynamic light scattering (DLS), microscopy, UV–Visible spectroscopy and small angle neutron scattering (SANS). The drug in the formulation was not in the oligomer form but in a competent uptake form, as shown by the UV–Visible spectroscopy. The DLS and microscopy depicted the product to consist of spheres (∼1 µm). The SANS experiment using deuterium contrast matching of the drug cores revealed a thin layer span of 5.6 nm, which is similar, but slightly larger as compared to the biological lipid membranes. The finding offers opportunities for further improvements of the formulation, e.g., by surface modification.A soluble core‐shell formulation ‘AmbiShell’ of the hydrophobic antifungal polyene drug Amphotericin B was generated from drug, lecithin, and gelatin. The span of the lipid–gelatin shell was estimated by neutron scattering SANS with deuterium contrast matching of the drug core.