In vitro stability and in vivo sub-chronic toxicity studies of thiamine nanoliposomes
Syeda Juveriya Fathima and Farhath Khanum
Department of Biochemistry and Nanosciences,
Defence Food Research Laboratory (DRDO), Siddharthanagar, Mysore, India-570011
Nanoliposomes have been used for carrying different therapeutic agents because of the advantage in improved absorption, bioavailability and target delivery. The aim of the study was to prepare nanoliposomes containing thiamine hydrochloride and study their physicochemical stability as this vitamin is highly unstable.
Phosphatidylcholine was used as an edible encapsulant to prepare thiamine nanoliposomes using high speed homogenization method with average size (150 nm) and zeta potential (-34mV). Atomic Force Microscopy and Scanning Electron Microscopy confirmed the size, spherical nature and smooth surface of the nanoliposomes. Differential Scanning Calorimetry and Thermogravymetric analysis evidenced that the nanoliposomes were stable up to 300 ˚C. The functional group analysis was done using Fourier transform infrared spectroscopy and crystalline structure was depicted by x-ray diffraction. Storage studies indicated that the nanoliposomes were highly stable up to 3 months at different temperatures. In vitro digestion of immediate release of liposomes in simulated environment revealed that the particles subjected to mouth and stomach condition were found to be intact (120nm and 117nm) whereas the ones that were subjected to simulated intestinal condition were broken down to smaller particles (45nm). Sub-chronic toxicity studies were carried out in healthy, Balb/C mice according to OECD guidelines. The animals were sacrificed; the blood was collected for hematological analysis. Major organs were collected for histological examinations. No obvious histological changes were observed in test similar to that of control group. Thus, nanoencapsulation protected the vitamin from adverse environmental conditions until it reaches the desired site of action.