Nanocochleates: innovative nanocarriers to enhance oral bioavailability of andrographolide

Nanocochleates are cylindrical microstructures that consist of a series of lipid bilayers. They have a unique multilayered structure consisting of solid, lipid bilayer sheet rolled up in a spiral or in stacked sheets, with little or no internal aqueous space [1]. They are stable phospholipid-cation precipitates composed of simple, naturally occurring materials such as lecithin, phosphatidylserine, phosphatidylcoline, phosphatidic acid and calcium ion. Andrographolide (AG) is the main active ingredient of Andrographis paniculata (Burm. f.) Nees, which is used in Chinese medicine against inflammation, internal fever and upper respiratory tract infection and diarrhea due to bacteria and virus [2]. Aim of our work was to develop andrographolide loaded nanocochleates in order to improve its dissolution and bioavailability. Unilamellar vesicles were prepared according to the film hydratation method from P90G (lipid), AG and cholesterol following sonication and ultracentifugation until obtaining nanoliposomes suspension. Nanocochleates were prepared by trapping method. A solution of CaCl2 (0.1 M) was added dropwise into preformed nanoliposomes under magnetic stirring at room temperature. Transmission electron microscopy exhibited nanocochleates as tubular rod structures with an average diameter of 132.2 ± 3nm, a polydispersity of 0.19 ± 0.02, and a zeta potential of -15.9 ± 1.1 mV. The average drug-entrapment efficiency was 95.6%± 0.54. The gastrointestinal absorption of AG-loaded nanocochleates was simulated in vitro by PAMPA assay using HPLC-DAD analysis. Cochleates acted as delayed release delivery vehicles.