Supercritical Antisolvent Precipitation Process

This work consists of the steps for the assembly of a Supercritical Antisolvent Precipitation laboratory equipment and evaluation of the parts acquisition costs. A flow diagram with all components was developed, a complete list of all necessary components was presented, and an estimate of the acquisition of these parts in Brazil was reported. The stages of construction along with the importance of each component in the equipment were discussed. An equipment designs were presented as a result of the current work that serve as a basis for consulting future work on the development of new equipment.

A supercritical particle formation equipment, designed and constructed by our research group, was validated in this study using supercritical CO₂ as an antisolvent. Ibuprofen sodium salt was successfully micronized by supercritical antisolvent (SAS) precipitation. Ethanol and CO₂ was used as solvent and antisolvent, respectively, and the effect of the operating conditions on the precipitation yield, residual organic solvent content and particle morphology were evaluated using a split-plot experimental design and the analysis of variance (ANOVA) method. This study showed that when selecting appropriate process conditions, it is possible to produce a sheet-like morphology, which is the best for tableting purposes, with high precipitation yield (70%) and low residual solvent content (4.7 mg kg⁻¹).

High Turbulence Extraction Assisted by Ultrasound combined with Supercritical Antisolvent Fractionation (SAF) was done to intensify the recovery of bixin and phenolic compounds from semi-defatted annatto seeds. Annatto seeds are extensively used due to its colorant properties and bioactive potential in human health. Modifications were performed in the SAF experimental apparatus in order to prevent losses of product. Results show that supercritical fractionation resulted in particle yields between 72.2–80.5%, 20–50% phenolics, and 66% bixin.

Efficient encapsulation techniques and development of special delivery systems enhance the stability of target compounds, enabling their processing and application. Supercritical fluid extraction of emulsions (SFEE) is a promising alternative to process natural target compounds, due to its suitability to encapsulate poorly water-soluble compounds in an aqueous suspension, providing products with controlled particle size, stability and without toxicity. This chapter provides technological aspects and recent data (2016–2018) on the application of SFEE delivery systems to encapsulate compounds of great interest to the food and non-food industry.

Surfactants are widely used in the food industry to form and stabilize emulsion-based food and beverage products. The use of natural surfactant to replace the synthetic ones is a recent demand in industries. In this work, first it was evaluated the influence of hydrostatic pressure levels (up to 10 bars applying nitrogen), oily phase type and surfactant type. In addition, we propose a novel surfactant for the formulation of emulsions constituted of concentration of saponin-enriched extract. The extract containing saponins was obtained from pressurized hot water extraction of Brazilian Ginseng (Pfaffia glomerata) roots. The emulsions containing saponin extract were used for further processing by Supercritical Fluid Extraction of Emulsions (SFEE), using an oily bixin-rich extract from annatto seeds (Bixa orellana L.) as core material (extracting solution from hot ethyl acetate pressurized extraction). Since, the final product of SFEE achieved a low residual ethyl acetate concentration (9.4 ppm). Regarding droplet size similar results were obtained for the emulsion (549 nm) and the produced suspension (569 nm), which were 24.74% lower than the droplet size obtained in process not assisted with pressurized nitrogen atmosphere (730 nm). This work proposed the use of this alternative biosurfactant and the process that we named Ultrasound Emulsification Assisted by Nitrogen Hydrostatic Pressure (UEANHP), during the emulsification preparation step of the SFEE process.

The effects of several operational parameters (pressure, temperature, CO₂ flow rate, solution flow rate, injector type, and concentration of solute in the ethanol solution) during Supercritical AntiSolvent (SAS) precipitation process on the energy consumption cost per unit of manufactured product were investigated using experimental design technique. In this work, two different injectors were used. A completely randomized experiment would eventually require a modification of the apparatus after each experimental run. To avoid this, the experimental runs were done accordingly with a split-plot experimental design. For this study, Ibuprofen sodium salt was used as a model solute, ethanol was used as solvent, and CO₂ was used as antisolvent. This supercritical fluid-based has been used successfully for several food and pharmaceutical applications since the production of small micro- and nanometer-sized particles have attracted growing interest in these industries. Focusing on energy saving, an SAS precipitation process was simulated using the SuperPro Designer simulation platform. The effect of temperature versus concentration of ethanolic solution and pressure versus solution flow rate interactions on the energy consumption cost per unit of manufactured product was demonstrated. The lowest estimated energy cost per unit of manufactured product was obtained using an ethanolic solution of 0.04 g mL⁻¹ at 12 MPa of pressure and a solution flow rate of 1 mL min⁻¹. This result was independent of the temperature. Thus, the present work reports a systematic energetic-economic study of the supercritical antisolvent micronization process, aiming increase knowledge about this process and its further incorporation by the food and pharmaceutical industries.