Conjugated linoleic acid loaded nanostructured lipid carriers (NLC): optimization of particle size by response surface methodology

Conjugated linoleic acid (CLA) is a type of nutraceuticals which can be used in functional food development however، it is sensitive to oxidation. Nanostructured lipid carriers (NLC) were used for the encapsulation of conjugated linoleic acid by hot homogenization method. Among four different solid lipids used in the production of this system (precirol ATO-5، Compritol ATO-888، Cacao butter and lauric acid) only precirol was able to produce acceptable particle size and structure. On the next step، on the basis of response surface method and central composite design، various concentrations of precirol and aqueous phase surfactant (poloxamer) and different ratios of liquid to solid lipid (conjugated linoleic acid to precirol) were used to find the optimum sample of CLA bearing NLC. The particle size and particle size distribution (Span) were in the range of 75-2040 nanometer and 0. 44-5. 16، respectively and it was observed that by increasing the concentrations of solid lipid and aqueous phase surfactant، the particle size increased considerably. Also، increment in liquid to solid lipid ratio enhanced particle size stability. The NLC formulation containing 2% (w/v) surfactant، 2% (w/v) precirol solid lipid and 50% of CLA to solid lipid ratio was chosen as optimum sample by 93 nm particle size and was stable at 4˚C during 45 days of preservation.