No abstract

A modified supercritical antisolvent method, aiming at high yielding and high loading, is developed for preparation of drug-loaded polymeric nanoparticles. The modified method consists of three alternate stages: injecting solution via a nozzle into a precipitation vessel filled with supercritical CO 2 , static agitation, and washing of precipitated particles with supercritical CO 2 . The process stages are continuously repeated until ending injection of a desired amount of solution. The ultrasound operates during the entire process. Poly(lactic-co-glycolic acid) (PLGA) and curcumin are model components. The influences of the process parameters on the yielding and loading are investigated. The maximum yield of the curcumin−PLGA nanoparticles 50 nm in size and the curcumin loading in it reach 96% and 45%, respectively. High yield, high loading, and uniform size are attributed to the efficient mixing between solution droplets and antisolvent, and sequential washing using an antisolvent under ultrasonic agitation. Experimental data are fitted and optimized by neural network simulation.

Curcumin is the main gradient of “Turmeric” a famous Indian spice and food additive. The marvelous nutritional and medicinal effects of curcumin made it a good alternative to some conventional drugs and food flavoring or coloring materials. However, the low solubility of curcumin is a challenging hindrance which should be seriously addressed. In this work, we prepared nano-curcumin with enhanced aqueous dispersion and dissolution rate. Ultrasonic-assisted supercritical anti-solvent (UA-SAS) technique was used to convert the commercial curcumin to uniform distributed nano-particles with the average size of 20 nm and yielding of 65%. The effect of process parameters including pressure, temperature, solution flow rate, and nature of organic solvent on the average particle size and yielding of products was investigated. The morphology, size, and crystalline pattern of processed curcumin particles were characterized by scanning electron microscopy, mean particle size analyzer, and X-ray diffraction. The champion specimen was achieved when the supercritical fluid was employed at 16 MPa and 35°C. Aqueous suspension of processed nano-curcumin can be stable for more than 2 months. In vitro dissolution experiments showed a remarkable enhancement in dissolution rate of UA-SAS-treated curcumin respecting to the commercial curcumin powder.