Synthesis and evaluation of solid lipid nanoparticles loaded with bovine serum albumin prepared by different methods

.We evaluated the effect of different synthesis methods of solid lipid nanoparticles (SLNs) loaded with bovine serum albumin (BSA) on parameters including particle size, polydispersity index, loading capacity and % entrapment efficiency including release study. We investigated the binary fatty acids mixtures for test protein BSA. Different techniques were used as micro emulsion, ultrasound homogenization and double emulsification-evaporation for the BSA loading of SLNs. With the increase in BSA content from 0-10%, indicated an increase in the size and decrease in polydispersity index. The stability of SLNs loaded with BSA was examined by measuring the zeta potential and all formulations were found to be quite stable. Release study and kinetic models were applied to assess BSA release profile from different formulations of SLNs. The particle size of BSA loaded SLNs was reduced to 89.67 ± 4.88 nm when PEG 6000 and Brij were used as 0.25% and 1.5% of total formulation (F5). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier-transform infrared spectroscopy (FTIR) indicated the chemical stability of BSA which was used to load SLNs in different formulations. SLNs from the combinations of solid and liquid lipids had enhanced the physicochemical properties and permitted controlled release of BSA for up to 10 days. The study also evaluated the addition of polyethylene glycol which reduced the particles size and enhanced % entrapment efficiency. The release of BSA from SLNs was followed zero order rate kinetics and diffusion-controlled. Different mathematical models, i.e., zero order, first order, Higuchi and Korsmeyer-Peppas models were found best fit to BSA release profile of all formulations of SLNs.