Development of lipid emulsion for parenteral nutrition

Abstract

The preparation method of parenteral lipid emulsion was studied. The medium chain triglycerides (MCT oil) and long chain triglycerides (soybean oil) were used at concentrations of 5%, 10% and 20%. The emulsifiers used were soy lecithin, synthetic nonionic surfactants; namely, Cremophor EL, poloxamer 188, Solutol HS15 and Tween 80. The emulsifiers were used either alone or in combination between soy lecithin and synthetic nonionic surfactant. The methods of preparation were varied in homogenization time, pressure and cycles through high pressure homogenizer. The formulations were sterilized by autoclaving. The results indicated that formulations composed of the combination of soy lecithin and Tween 80 and soy lecithin and poloxamer 188 could form stable emulsion. The lipid emulsion containing 10% soybean oil emulsified by 1.71% soy lecithin and 1.29% Tween 80 was the best formulation and was called "10% Pharmalipid". The particle sizes (d(v,0.5)) of such formulation before and after autoclaving were 0.31 and 0.33 um, respectively, which were insignificantly different (p>0.05). The pH, osmolality and the value of zeta potential of the emulsion were 6.8, 337 mOsm/kg water and -33.52 millivolts, respectively. The pH and zeta potential were slightly decreased upon storage at room temperature while the d(v,0.5) and osmolality remain constant. The developed emulsion and five commercial lipid emulsions; namely, 10% and 20% Intralipid, 10% and 20% Lipofundin MCT/LCT and 10% Lipofundin-S were used to prepare the total nutrient admixtures (TNA) by mixing with amino acid and dextrose solution. The physical stability and physicochemical properties of TNA were analyzed immediately after mixing and after storage at room temperature for 24 hours. The pH of TNA system was weakly acidic and remained constant throughout the period of study and the osmolality was slightly hyperosmotic. Moreover, the zeta potential was slightly decreased and the d(v,0.5) of emulsion in TNA systems remained close to that of the original lipid emulsion.