Batch production of micron size particles from poly(ethylene glycol) using supercritical CO2 as a processing solvent

Abstract

The major advantage of using supercritical carbon dioxide (CO 2 ) as a solvent in polymer processing is an enhancement in the free volume of a polymer due to dissolved CO 2 , which causes a considerable reduction in the viscosity. This allows spraying the polymer melt at low temperatures to produce micron size particles. We have used supercritical CO 2 as a solvent for the generation of particles from poly(ethylene glycol) (PEG) of different molecular weights. Since PEG is a hydrophilic compound, it is a most commonly used polymer for encapsulating a drug. PEG particles with different properties may allow keeping a good control over the release of the drug. It has been possible to produce particles with different size, size distribution, porosity and shape by varying various process parameters such as molecular weight, temperature, pressure and nozzle diameter. A flow and a solidification model have been applied in order to have a theoretical insight into the role of different parameters. ᭧

Preparation of micro particles of functional pigments by gas-saturated solution process using supercritical carbon dioxide and polyethylene glycol

“…It might be explained that CO 2 could not escape easily due to rapid solidification of the particles due to the temperature effect on particle formation. Nalawade et al [1] also reported the similar effect of temperature on micro particle formation by PGSS using SC-CO 2 . In contrast, at constant temperature the particle size of functional compounds with PEG decreased with the increase in pressure.…”

“…Pharmaceutical industries always need fine particles without using organic solvents [1]. Traditionally, some methods are used for producing fine particles, including milling, grinding, spray drying, and recrystallization from solution.…”

“…PEG is available in different states such as liquid or solid depending on the molecular weight. In the solid state, PEG is mainly used in particle formation for pharmaceutical applications, such as drug carriers [1]. The functional compounds, fucoxanthin and astaxanthin, are the carotenoids found in the animal and plant kingdoms.…”

High-pressure rheological analysis of CO2-induced melting point depression and viscosity reduction of poly(ε-caprolactone)

“…CO 2 has been exploited as a solvent for polymerisations [7,8], as a foaming agent [1,[9][10][11][12][13], for precipitation/separation [14], particle formation [15,16] and encapsulation [17].…”

Green process for green materials: viable low-temperature lipase-catalysed synthesis of renewable telechelics in supercritical CO 2

“…In recent years interest in the use of compressed CO2 as a reaction medium or plasticiser for polymer synthesis and processing has increased steeply (32)(33)(34)(35). CO2 has been exploited as a solvent for polymerisations (36,37), as a foaming agent (32,38), for precipitation/separation (39), particle formation (40,41) and encapsulation (42). High-pressure CO2 is a good solvent for many small molecules and it is very effective at plasticising and effectively liquefying many polymers at temperatures below their glass transition temperature (Tg) and melting point (Tm) (33,41,(43)(44)(45)(46)(47)(48)(49)(50)(51)(52), therefore opening up new opportunities for polymer synthesis and modification.…”