Particle formation and micronization using non-conventional techniques- review

Abstract

Due to growing concerns regarding health, safety and the environment, non-conventional methods for particle formation and micronization that are either solvent-less or use environmentally acceptable solvents such as carbon dioxide have come into favor. Supercritical CO (sc CO ) (T>31.1°C, P>7.3MPa) has been used in food and pharmaceutical industries to minimize the use of organic solvents, produce new food products, produce environmentally superior food products and to process and micronize (0.1-5μm) pharmaceuticals. Control of particle size increases the dissolution rate of drugs into the body. Techniques that use sc CO eliminate inherent drawbacks of conventional methods such as thermal or mechanical degradation of the product, poor control of the particle size and morphology, lack of brittleness of some polymers and low encapsulation efficiency. Several techniques have been reported for the particle formation and micronization using supercritical fluids that have been successfully scaled up for commercial use. Supercritical CO has also been used to develop applications for medicines, essential oils, vitamins, food grade polymers, catalysts and pigments. This review highlights the process mechanism of supercritical fluid based techniques as well as some applications on particle formation and micronization.

Screening design of experiment applied to the supercritical antisolvent precipitation of quercetin

“…Supercritical fluids (SCFs) are increasingly used as an alternative in nanoprecipitation techniques [5][6][7] for high value added products that can be used in the pharmaceutical, cosmetic, and food industries. The use of SCFs offers advantages such as higher product quality in terms of purity, more uniform dimensional characteristics, a substantial improvement in environmental aspects and, furthermore, their properties can be adjusted continuously by altering the experimental conditions [8][9].…”

Assessment of the liquid mixture density effect on the prediction of supercritical carbon dioxide volume expansion of organic solvents by Peng-Robinson equation of state

“…It is noteworthy that for this calculation parameter l of PR-LCVM-UNIFAC as well as parameters k ij and l ij of PR-QMR EOS were regressed for each binary system using the objective function expressed by Eq. (3). The values of parameters k ij and l ij are in the range between 0 and 0.02 but for polar components they can result in negative ones.…”

“…For this reason it can be considered as a clean technology compared to conventional micronization techniques such as freeze-drying, spray drying, solvent evaporation or jet milling. Also SCF physical and transport properties are intermediate between those of a gas and a liquid offering the possibility of process intensification [1,2,3].…”

Soybean Oil Transesterification for Biodiesel Production with Micro-Structured Calcium Oxide (CaO) from Natural Waste Materials as a Heterogeneous Catalyst

“…This technique consists of solubilizing CaO into conventional liquid solvents. These solvents are then saturated by supercritical CO 2 , resulting in the controlled precipitation of nanocrystalline CaO by the anti-solvent effect [24,25]. Therefore, it will be possible to optimize the nanoparticle size by tuning the operational conditions.…”