Liposomes in cosmetics: which kind of phospholipid? Which loading method?

Phospholipids of different origin (egg and soya) and purity were used to prepare liposomes by sonication. Loading of these vesicles was performed by means of two different techniques using a fluorescent lipophilic model molecule. The stability of the aggregated structures was checked by addition of increasing amounts of a surfactant to the liposome dispersion. No remarkable differences were observed in either the stability in regard to surfactant-induced breakage or the loading capacity of liposomes respectively prepared with 99% pure egg phosphatidylcholine or with the vegetable phospholipid, a commercial product that had a much lower purity. The comparison of the two loading methods indicated that incorporation of the model molecule within the vesicle structure was higher when the fluorescent marker was added before sonication.