Wengang Li

Evaluation of Antioxidant Ability In Vitro and Bioavailability of trans-Cinnamic Acid Nanoparticle by Liquid Antisolvent Precipitate

TCD is a kind of organic acid that is isolated from cinnamon bark or benzoin. TCD has significant antioxidant activity and is widely used in pharmaceutical, cosmetic, and food additives. But TCD has shortcomings of low bioavailability due to poor water solubility. Therefore, we use ethanol as a solvent, deionized water as antisolvent, and hydroxypropyl methylcellulose HPMC as the surfactant to prepare TCD nanoparticle powder. The optimum preparation conditions were determined as follows: TCD-ethanol solution concentration was 170 mg/mL, the volume ratio of antisolvent was 4 times that of solvent, and the amount of the surfactant was 0.3% stirred for 10 min by 2500 rpm; TCD nanoparticle with a mean particle size MPS of 130±12.5 nm is obtained under the optimum conditions. SEM, FT-IR, LC-MS/MS, XRD, and DSC were used to characterize the TCD nanoparticle. The results showed that the chemical structure of TCD nanoparticle was not changed, but the crystallization was significantly reduced. Solubility, dissolution rate, antioxidant activity, the in vitro transdermal penetration, and bioavailability of TCD nanoparticles were all much better than these of the raw TCD. These results suggested that TCD nanoparticle might have potential value to become a new oral or transdermal TCD formulation with high bioavailability.

Preparation, characterization, and dissolution rate in vitro evaluation of total panax notoginsenoside nanoparticles, typical multicomponent extracts from traditional chinese medicine, using supercritical antisolvent process

Total Panax notoginsenosides nanoparticles, typical multicomponent extracts from traditional Chinese medicine, were prepared with a supercritical antisolvent (SAS) process using ethanol as solvent and carbon dioxide as antisolvent. The optimum conditions were determined to be as follows: TPNS solution concentration of 2.5mg/mL, TPNS solution flow rate of 6.6 mL/min, precipitation temperature of 40°C, and precipitation pressure of 20MPa. Under the optimum conditions, TPNS nanoparticles with a MPS of 141.5 ± 18.2nm and total saponins amounts (TSA) of 78.9% were obtained. The TPNS nanoparticles obtained were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimeters (DSC), and high performance liquid chromatography (HPLC). The results showed that the chemical and crystal structure of the obtained TPNS nanoparticles has not changed. Dissolution in vitro studies showed that the solubility and dissolution rate of notoginsenosides R1 and ginsenoside Rb1 in TPNS nanoparticles are higher than these in raw TPNS, with no obvious difference in Rg1. These results suggest that TPNS nanoparticles can be helpful to the improvement of its bioavailability for the treatment of cardiovascular diseases.