Preparation of Solid Lipid Nanoparticle-Ferrous Sulfate by Double Emulsion Method Based on Fat Rich in Monolaurin and Stearic Acid

Abstract

Ferrous sulfate is one type of iron that is commonly used in iron supplementation and fortification in food products, but it has low stability and an unfavorable flavor, causing its use to be limited. Encapsulation in a solid lipid nanoparticle (SLN) system is one technology that offers stable active compound protection and a good delivery system; however, a solid lipid matrix should be selected which has good health effects, such as glycerol monolaurate or monolaurin. The purpose of this study was to obtain SLN-ferrous sulfate based on stearic acid and fat rich in monolaurin. SLN-Ferrous sulfate was synthesized at various concentrations of monolaurin-rich fat (20%; 30%; 40% w/w lipid) and various concentrations of ferrous sulfate (5%; 10%; 15% w/w lipid). The results showed that the use of monolaurin-rich fat 40% w/w lipid and 15% w/w ferrous sulfate produced the best characteristics with high entrapment efficiency and loading capacity of 0.06%. The Z-average value of SLN was 292.4 nm with a polydispersity index (PI) of 1.03. SLN-ferrous sulfate showed a spherical morphology, where the Fe trapped in the SLN was evenly dispersed in the lipid matrix to form a nanosphere system. Preparation of SLN-ferrous sulfate by double emulsion method based on stearic acid and fat rich in monolaurin effectively encapsulated ferrous sulfate with high entrapment efficiency and good physicochemical properties.

Solid Lipid Nanoparticles: Review of the Current Research on Encapsulation and Delivery Systems for Active and Antioxidant Compounds

“…The ultrasonication method and high-speed homogenization can be used in the fabrication of SLNs effectively [ 45 , 81 , 82 ]. The initial step is usually conducted by mixing the components of the active compounds that are put into the melted lipid, and then the liquid phase (which has been heated at the same temperature) is added to the previous mixture and emulsified with ultrasonication or by using a high-speed stirrer.…”

“…The crystallized SLNs are collected by centrifugation at 12,000 rpm for 60 min at 4 °C [ 88 ]. SLNs ware then lyophilized using a freeze-dryer and stored in a refrigerator [ 45 , 79 ]. High-shear homogenization combined with ultrasonication is the recommended method and has been widely used because of the ease of preparation and good results.…”

“…The surfactants used to form w/o emulsions can be lecithin or monoglycerides. Then, the w/o microemulsion formed is added to a mixture of water, surfactant, and cosurfactant to form a w/o/w double emulsion [ 43 , 45 ]. Generally, Tween 80 is used to form w/o/w emulsions.…”

“…Surfactants act as a barrier between the lipid matrix on the outside of the particles. Solid lipids that can be used are saturated fats in the form of free fatty acids, mono- and diglycerides, triglycerides, and other fatty acid esters that act as binders of active substances or drugs in the lipid matrix [ 43 , 44 , 45 ].…”

“…The use of lipids with high melting temperatures can form SLNs with large sizes due to the high viscosity of the diffuse phase. The use of solid lipids with high melting points can also increase the polydispersity index, which indicates that the particle size of SLNs is not uniform [ 45 , 58 ]. The length of the fatty acid chains in lipids also influences the characteristics of the SLNs.…”