Liposomes in cosmetics (II): entrapment of a hydrophylic probe

Phospholipids of different origin (egg and soya) and purity were used to prepare liposomes by sonication. Loading of these vesicles with a fluorescent hydrophilic model molecule (calcein) was carried out by means of two different methods. No appreciable differences were observed in the loading capacities of liposomes prepared with the two products. Obtained results indicated that the fraction of incorporated or absorbed calcein was always very small with respect to the total amount of this substance used for the preparation of the vesicles; furthermore, the quantity of hydrophilic probe in the vesicle structure was remarkably affected by the loading method. The results of this investigation allowed us to consider the possible incorporation, inion the vesicles, of additives that can be present in a formulation containing liposomes.