Preparation, Characterization and Evaluation of Antioxidant Flavonosomes

Abstract

The objective of the present study was to prepare flavonosomes loaded with kaempferol and curcumin in order to improve the bioavailability of the flavonoids. The flavonosomes loaded with kaempferol and curcumin were prepared using bulk co-loading method using lecithin as the lipid molecule. The particle size of the flavonosomes was determined using zeta sizer and ranged from 497.3 nm to 167.1 nm. The results indicated that increase the ratio of lipid to extract was able to reduce the particle size of the flavonosomes. The flavonosomes prepared using 4:1 ratio of lipid to flavonoids were found to be rigid, spherical as seen in SEM with smooth regular surface. Sharp and distinct endothermic peaks in DSC revealed the formulation of stable flavonosomes due to molecular interactions between the extract and lecithin. The entrapment efficiency of flavonosome preparation F4 was determined by measurement of the non-entrapped flavonoids and subtracting from the total flavonoids used to obtain the flavonoids entrapped in the formulation. The entrapment efficiency of F4 has been calculated to be 94.12%. The flavonosome F4 was studied for release of the entrapped flavonoids by dialysis method. The amount of flavonoids released at 1, 2, 3, 4, 6, 8, 10 and 12 hours was determined using UV spectrophotometry. After the first hour, the entrapped flavonoids released in a steady manner from the flavonosome depicting and almost complete release (90.52% for kaempferol and 94.67% for curcumin) from the formulation. The flavonosomes were found to be stable under the storage conditions. The best formulation with respect to particle size and anti-inflammatory action was F4 that contained 4:1 ratio of lecithin: flavonoids. DPPH radical scavenging assay was used to determine the antioxidant action of the individual flavonoids and the flavonosome formulation. It was found that the formulation F4 was having higher antioxidant activity in comparison to kaempferol and curcumin. The IC50 of kaempferol, curcumin and flavonosome were found to be 228.20 µg/mL, 175.51 µg/mL and 158.19 µg/mL respectively. Keywords: Flavonosome, Kaempferol, Curcumin, Bulk co-loading, antioxidant