First Vesicular Self‐assembly of a Trihydroxy‐Diterpenoid Andrographolide in Aqueous Medium: Entrapment and Release of Fluorophore and Anti‐Cancer Drug Doxorubicin

Abstract Andrographolide, a naturally occurring trihydroxy diterpenoid, was extracted from the leaves of Andrographis paniculata . The molecule spontaneously formed vesicular self‐assemblies in aqueous binary liquid mixtures such as DMSO‐water (1 : 2), THF‐water (1 : 2), DMF‐water (1 : 2) and cyclohexanol‐water (2 : 1). The characterizations of the vesicular self‐assemblies were carried out by optical, atomic force and electron microscopic techniques, x‐ray diffraction and FTIR studies. The encapsulation of anionic fluorophore carboxyfluorescein and the cationic fluorophores rhodamine B and anti‐cancer drug doxorubicin by the self‐assemblies of andrographolide was also demonstrated. The entrapped drug molecules were released on treatment with the vesicle‐rupturing agent Triton X‐100.