STUDY OF THE INFLUENCE OF SYNTHESIS PARAMETERS ON THE AVERAGE HYDRODYNAMIC RADIUS OF VITAMIN E (ALPHA-TOCOPHEROL ACETATE) MICELLES

Abstract

The aim of this work is to study the effect of synthesis parameters on the average hydrodynamic radius of vitamin E micelles (alpha-tocopherol acetate). A multivariate experiment was carried out, including 3 input parameters and 3 levels of variation. The following parameters were chosen as input parameters: synthesis temperature (t), vitamin E concentration (C (E)) and surfactant concentration (Tween 80 or Kolliphor HS 15) - C (surfactant). The average hydrodynamic radius (Rsr) was considered as an output parameter. As part of the study of the effect of the synthesis parameters on the average hydrodynamic radius of vitamin E micelles stabilized by Kolliphor HS 15, it was found that an increase in the medium temperature leads to a proportional increase in the average hydrodynamic radius of micelles of vitamin E nanoemulsions stabilized by Kolliphor HS 15. Dependence of the average hydrodynamic radius of micelles of nanoemulsions on the concentration of vitamin E has a parabolic appearance. The dependence of Rsr of micelles of vitamin E nanoemulsions on the concentration of Kolliphor HS 15 has the form of a parabola, the branches of which are directed downward. Optimal conditions for obtaining vitamin E nanoemulsions stabilized by Kolliphor HS 15, in which Rsr ≤ 100 nm: t = 30 - 35°C, C (Kolliphor HS 15) = 0.05 - 0.15 or 0.45 - 0.55 mg/ml, C (E) = 0.4 - 0.5 mg/ml. As part of the study of the effect of the synthesis parameters on the average hydrodynamic radius of vitamin E micelles stabilized with Tween 80, it was found that the dependence of the output parameter Rsr on the temperature of the medium and the concentration of Tween 80 has a linear form. The smallest average hydrodynamic radius of micelles of vitamin E nanoemulsions stabilized with Tween 80 is observed in the region with C (Tween 80) = 0.4 - 0.5 mg/ml and t = 30 - 35°C. The largest average hydrodynamic radius of micelles of vitamin E nanoemulsions stabilized with Tween 80 lies in the region with C (Tween 80) = 0.1 - 0.2 mg/ml and t = 65 - 70°C. At high concentrations of Tween 80, the formation of samples with high viscosity (η = 6000 - 8000 cP) was observed, which indicates the formation of liquid crystal structures. The dependence Rsr of micelles of nanoemulsions of vitamin E on the concentration of vitamin E has the form of a parabola, the branches of which are directed downward. Optimal conditions for obtaining vitamin E nanoemulsions stabilized with Tween 80, in which the value of the average hydrodynamic radius of micelles takes minimum values are t = 30 - 35°C, C (Tween 80) = 0.4 - 0.5 mg/ml, C (E) = 0.1 - 0.2 mg/ml and 0.6 - 0.7 mg/ml.