Malvern zeta sizer apparatus

The content of lycoene in nanospheres was determined by high-performance liquid chromatography (HPLC) as previously described.[24 (link)] Briefly, 20 mg of prepared nanospheres were dissolved in 0.5 ml of dimethyl sulfoxide (DMSO) and mixed with 0.98 ml of methanol: Water (50:50 vol./vol.) solution. Then, the 50 μl of mixture was injected into the HPLC column. In the HPLC analysis, a C30 column (3 μm, 150 × 4.6 mm, YMC, Wilmington, NC, USA) was used. The mobile phase for the determination of the lycopene was methanol/methyl-tert-butyl ether/water (83:15:2, v/v/v, with 1.5% ammonium acetate in the water; solvent A and methanol/methyl-tert-butyl ether/water (8:90:2, v/v/v, with 1% ammonium acetate in the water; solvent B at a flow rate of 1.2 ml/min and then the percentage of lycoene loading was then calculated as:
Amount of lycoene in nanospheres × total volume tested × 100/total sample volume × initial amount of nanospheres.
The particle size, zeta-potential, and polydispersity index of the lycopene-loaded nanospheres were evaluated using Malvern Zetasizer apparatus (Malvern Instrument, Worcestershire, UK), as reported previously.[22 (link)] Briefly, the particle size and zeta-potential of nanospheres were measured at angles of 90° and 120° at 25°C, respectively. These experiments were done in triplicate.