Caffeine Encapsulated in Small Unilamellar Liposomes: Characerization and In Vitro Release Profile

Liposomes containing hydrogenated soy phosphatidylcholine (PCH), with or without cholesterol (CHOL) and caffeine (CAF), were prepared by sonication and characterized for encapsulation efficiency and mean diameter. Dynamic light scattering assay showed that the incorporation of CHOL decreased significantly the size of the liposomes and led to a more heterogeneous distribution of size raising the CAF encapsulation efficiency. The in vitro drug release studies showed that the encapsulation of the CAF in liposomes produced a reduction in the release rate and the inclusion of CHOL in the liposome formulation delayed still further the release of the CAF.