Destabilization of egg lecithin liposomes on the skin after topical application measured by perturbed gamma gamma angular correlation spectroscopy (PAC) with 111In.

Unilamellar and oligolamellar liposomes were topically applied to the skin of porcine ears. Perturbed angular correlation spectroscopy of 111In-DTPA, initially entrapped into the liposomes, was used to study the release kinetics of the hydrophilic probe. After drying of the liposomal suspensions, a decrease of the time-integrated perturbation factor <G22(infinity)> within 30 min indicated destabilization of the liposomes and total marker release in the upper epidermal layers.