Finally, both rheology and acoustic spectroscopy indicated that addition of the oily phase caused minimal changes to the elastic character of the gel. This fact could indicate that the gel structure is characterized by weak polymer–polymer interactions, an advantageous characteristic for topical administration, as the sample is thus easier to rub into the skin. Nevertheless, the elastic properties of the gel-like structure even at elevated polymer concentrations were not strongly long-lasting, as demonstrated by the increase of the viscous contribution in the low frequency range during acoustic spectroscopy analysis. On the other hand, the 3–5% ( w/ w) concentration systems showed typical gel-like spectra, marked by the absence of crossover points between the dynamic moduli and by weak dependence on frequency. In fact, the mechanical spectra of the 0.5% and 1% ( w/ w) Sepineo samples were characterized by strong frequency dependence and multiple crossover points, typical of dilute polymer solution with no organized structure. Classical oscillatory analysis revealed that the dynamic moduli were very dependent on polymer concentration as this parameter increased, there was progressive improvement in the sample elasticity. The particle size of the oil droplets and the microrheological extensional moduli ( G′ and G″) of the systems were determined from acoustic parameters and used together with the classical oscillatory rheological tests to assess the stability of the systems. All the prepared systems were analyzed and characterized by oscillation rheology and acoustic spectroscopy. In this paper, gels were prepared using a Sepineo P 600 concentration between the 0.5% and 5% ( w/ w), and then emulsion gel was also prepared from the 3% Sepineo gel by adding a specific amount of almond oil. Sepineo P 600, a concentrated dispersion of acrylamide/sodium acryloyldimethyl taurate copolymer in isohexadecane, has self-gelling and thickening properties and the ability to emulsify oily phases, which make it easy to use in the formulation of gels and o/w emulsion gels.

Almond emulsion