Design and optimisation of phospholipid vesicles for topical betamethasone dipropionate

Betamethasone dipropionate is a topical corticosteroid widely used to treat common dermatoses and skin disorders. However, the poor skin penetration of traditional betamethasone dipropionate formulations can impair therapeutic outcomes. In the present study, betamethasone dipropionate was formulated in phospholipid vesicles to maximise its benefits and minimise its side effects. Liposomes and transfersomes were developed using the direct sonication method and thoroughly characterised by light scattering, cryo-transmission electron microscopy (TEM), small-angle x-ray scattering (SAXS), rheological analysis and skin permeation studies. Human skin epithelial-like cells were used to study how the phospholipid vesicles affected cell proliferation and morphology. Both the liposomes and transfersomes were nanosized, spherical and predominantly unilamellar, but the transfersomes were smaller, more homogeneous and stable on storage due to the presence of Tween® 80. The latter was also responsible for a higher viscosity, which decreased at 32 °C, the temperature of the skin surface, as determined by rheological analysis. Furthermore, tests of the formulations in skin cells showed the absence of cytotoxicity and increased skin permeation. Phospholipid vesicles represent a promising approach for betamethasone dipropionate delivery, as they are characterised by high stability and cytocompatibility. These properties may improve the therapeutic outcomes and minimise the side effects of betamethasone dipropionate, encouraging further investigation to confirm the effective and safe use of betamethasone dipropionate nanoformulations on the skin.