Today, liposomes are one of the most effective carriers systems employed in biological, pharmaceutical, medical and nutritional research. In order to optimize a liposomal formulation for the encapsulation, delivery and release of the entrapped material, it is necessary to study material passage through the lipidic and aqueous phases of the lipid vesicle. Towards this end, this article aims to review the mechanisms of bioactive transfer between different layers of a liposome and it also discusses about the bioactive release mechanism. Several methods of detection and observation of bioactive transfer in liposomal systems are presented.