Haakerheowin data manager v 4

Forty-eight hours after preparation of the gels, rheological measurements were determined in triplicate with a rotational rheometer (Haake Rheostress 1, Thermo Fischer Scientific, Karlsruhe, Germany) provided with a cone–plate setup (the gap between cone and plate was 0.106 mm), with a plate and a movable higher cone Haake C60/2° Ti (60 mm diameter, 2° angle). The rheometer was equipped with a Thermo Haake Phoenix II + Haake C25P temperature controller device (Thermo Fischer Scientific, Waltham, MA, USA) and operated by a HaakeRheowin^® Job Manager v. 4.0 (Thermo Fischer Scientific, Waltham, MA, USA) for testing and HaakeRheowin^® Data Manager v.4.0 (Thermo Fischer Scientific, Waltham, MA, USA) for analysis of the acquired data. Viscosity and flow curves were measured at 25 °C. The conditions of the shear rate ramp program adjusted a 3 min ramp-up period from 0 to 50 s⁻¹, a 1 min uniform-shear-rate period from 50 s⁻¹, and a ramp down from 50 to 0 s⁻¹ for 3 min. The rotational flow curve values were fitted to various mathematical model equations: Newton, Ostwald-de-Waele, Bingham, Casson, Cross, and Herschel–Bulkley [20 (link)]. The best fit of mathematical models was based on the correlation coefficient value (r). The mean viscosity value (Pa·s) was evaluated from the uniform share section at 50 s⁻¹ for each formulation.

The rheological measurements were performed in duplicate 24 h after gel preparation using a rotational rheometer (Thermo Scientific HaakeRheostress 1, Thermo Fischer Scientific, Karlsruhe, Germany) equipped with a cone plate set-up (0.105 mm gap between cone and plate) with a fixed lower plate and a mobile upper cone Haake C60/2° Ti (60 mm diameter, 2° angle). The rheometer was connected to a temperature control ThermoHaake Phoenix II + Haake C25P (Thermo Fischer Scientific, Waltham, MA, USA) and a computer provided with the HaakeRheowin^® Job Manager v. 4.0 (Thermo Fischer Scientific, Waltham, MA, USA) to carry out the tests and HaakeRheowin^® Data Manager v.4.0 (Thermo Fischer Scientific) to carry out the analyses of the obtained data. Viscosity curves (η = f( $\dot{\gamma }$ )) and flow curves (τ = f( $\dot{\gamma }$ )) were recorded at 25 °C. The shear rate ramp program included: a ramp-up period from 0 to 50 s⁻¹ for 3 min; constant shear rate period of 50 s⁻¹ for 1 min; and a ramp-down period from 50 to 0 s⁻¹ for 3 min. The data from the flow curves (τ = f( $\dot{\gamma }$ )) were fitted to different mathematical models equations: Newton, Bingham, Ostwald-de-Waele, Herschel-Bulkley, Casson and Cross [27 (link)]. Best fit of mathematical models was based on the correlation coefficient value (r). The viscosity mean value (Pa·s) was determined from the constant share section at 50 s⁻¹.

Viscosimetric measurements provide noteworthy information regarding formulation, application/sensorial properties and structural stability during shelf life. The rheological behavior of the creams was analyzed using a Haake^TM MARS^TM 60 Rheometer (ThermoFisher Scientific, Germany) with a controlled temperature maintained by a thermostatic circulator and a Peltier temperature module (TM-PE-P) for cones and plates. Data were analyzed with Haake Rheowin^® Data Manager v.4.82.0002 software (ThermoFisher Scientific, Germany). Throughout the experimental analysis, temperature was maintained at 32 °C. For each test, approximately 1.0 g of each formulation was placed on the lower plate before slowly lowering the upper geometry to the predetermined trimming gap of 1.1 mm. After trimming the excess material, the geometry gap was set at 1 mm. Rotational and oscillatory measurements were performed sequentially on each sample for a thorough rheological characterization [3 (link)]. Rotational tests enable us to evaluate small periodic deformations that determine breakdown or structural rearrangement and hysteresis, while oscillatory tests allow us to analyze material viscoelastic properties when they are exposed to small-amplitude deformation forces. All rheological studies were performed in triplicate.