Evaporative Deposition in Aqueous Solution (EPAS) is a newly developed technology for the preparation of micronized drugs. EPAS uses a rapid phase separation process to prepare water-insoluble drug nano or micro particles. First dissolve the drug in an organic solvent with a low boiling point, and then spray the solution through an atomizer into an aqueous solution containing a hydrophilic stabilizer or surfactant with a certain temperature to form an aqueous dispersion system, which is violent Atomization causes the organic solvent droplets containing drug molecules to quickly evaporate in the aqueous solution, forming a high degree of supersaturation of the drug solute, leading to rapid nucleation of drug molecules. Due to the evaporation of the organic solvent, the volume of the atomized droplets is significantly reduced. At the same time, the hydrophilic stabilizer or surfactant in the water phase competes to diffuse and aggregate on the surface of the drug particles to prevent the particles from growing further.
Fig.1 Mechanism of EPAS particle formation and stabilization
The EPAS process mechanism is shown in the Figure 1. The hydrophobic part of the surfactant is adsorbed on the surface of the drug particles, and the hydrophilic part extends to the water phase to form a space or electrostatically stable layer. The selection of the water phase temperature should take into account the rapid evaporation of organic solvents, the solubility of organic solvents in water, and the thermal decomposition of drug molecules. EPAS suspension drying can be achieved by spray drying, freeze drying and low temperature vacuum drying processes. The combination of the drug particles and the water-soluble stabilizer or surfactant can promote the rapid dissolution of the final drug product in the aqueous solution after drying. Since the particle formation stage and the drying stage are separated, the drying stage will not affect the rapid dissolution of the fine particles formed in the suspension.
CD Formulation has professional experience and technical personnel in micronization technology to reduce particle size. If you have insoluble or poorly soluble pharmaceutical active ingredients, please contact us in time to learn how micronization technology can help solve your formulation challenges, and let us transform your product from concept to commercialization.
EPAS process has many advantages compared with traditional spray process. The services provided by CD formulation to customers include:
According to customer needs, use aqueous evaporative deposition technology to prepare drug particles of corresponding size.
Provide a complete experimental data report.
If you have a requirement about aqueous evaporative deposition technology services, please contact us by phone or email, our colleagues will reply to you within three working days.