The formulation and characterization of near infrared-mediated size reversible ultrasound contrast agent / 药学学报

The drug-loaded ultrasound (US) contrast nanoparticles, which can effectively accumulate in the tumor to penetrate into its deep section, were prepared. After being heated or under the near infrared (NIR) light irradiation, the size of nanoparticles would transform from nanometer-scale to micrometer-scale in vitro, which can vastly enhance the effect of US imaging. We evaluated the size changes of the nanoparticles in vitro, investigating their effect in ultrasound imaging and distribution in vivo. Liposomes containing hydrophobic modified hollow gold nanospheres (HAuNS), doxorubicin (DOX) and perfluorohexane (PFH), which were referred to DOX and HAuNS loaded PFH liposome (DHPL), were prepared by thin film evaporation and ultrasonic technique. The morphology and size of DHPL were measured by transmission electron microscopy and particle size analyzer with dynamic light scattering (DLS) method. The agar gel pore model was used to investigate the enhanced effect of nanoparticles in vitro US imaging under the NIR light irradiation. The biodistribution of DHPL in 4T1 tumor-bearing mice after intravenous injection was measured by the in vivo imaging system. The DHPL were spherical at a particle size of 302 ±5 nm and polydispersity index of 0.195 ±0.018. The HAuNS loaded on phospholipid membrane was observed in transmission electron microscope (TEM) image. Under the NIR light irradiation (1 or 2 W·cm-2), the temperature of the solution containing the DHPL (0.2, 0.04, 0.02 g·L-1 in terms of HAuNS) rose rapidly. And a certain amount of micrometer-sized particles could be detected by the particle size analyzer when the temperature of the analyzer was raised to 52℃. The abundant microbubbles, which would enhance the effect of US imaging, were detected by ultrasonic diagnostic apparatus when the nanoparticles were irradiated by NIR light in the in vitro US imaging experiment. The in vivo distribution experiment showed that the DHPL could effectively accumulate in the tumor due to the enhanced permeability and retention effect (EPR effect) of the tumor. In this study, we successfully made a nanometer-micrometer reversible nanoparticles that can accumulate inside the tumor to provide a feasible scheme for US imaging in the tumor site and the combinational photothermal-chemotheraphy simultaneously.

Effect of nitrogen supply on biomass accumulating and root respiration dynamic changing of Glycyrrhiza uralensis / 中国中药杂志

This paper aimed to study the effect nitrogen supplying on biomass accumulation and root respiration dynamic change of Glycyrrhiza uralensis and reveal the metabolic pathway of root respiration impact the biomass accumulating of G. uralensis. Six groups of one-year-old G. uralensis were fertilized with total nutrition containing various nitrogen concentration (0, 0.5, 1, 2, 4, 8 mmol x L(-1)) every week. At the end of every month, from June to October, the volume respiration rate and biomass of different classes of root samples were determined, and the correlation between root respiration and biomass was analyzed. The results indicated a negative correlation between volume respiration rate and biomass, nitrogen supply significantly affected both root respiration and biomass of G. uralensis by reducing root respiration and increasing root biomass. Under 8 mmol x L(-1) nitrogen supplying, there existed the optimal inhibition of root respiration, which has increased biomass of G. uralensis.

Preparation of enteric microsphere of oleanolic acid dihemiphthalate sodium by salting-out action using spherical crystallization technique / 药学学报

<p><b>AIM</b>Enteric microspheres were prepared to prevent the interaction of drug with gastric acid and to improve its bioavailability.</p><p><b>METHODS</b>The enteric microspheres with a matrix structure were successfully produced using a spherical crystallization technique. Hydroxypropyl methylcellulose phthalate (HP-55), an enteric material, was coprecipitated with the drug by salting-out effect during the preparation process. A mixture of water and ethanol was chosen as a good solvent and dichloromethane was used as a bridging agent while 0.1 mol x L(-1) sodium chloride solution was selected as a poor solvent.</p><p><b>RESULTS</b>It is the first time to prepare microspheres by making the water-soluble drug and water-insoluble excipient coprecipitated. In vivo test demonstrated that the drug absorption from the enteric oleanolic acid dihemiphthalate sodium (OADHPS) microspheres was significantly prolonged compared to that with OADHPS powder after a lag-time. Furthermore, the drug bioavailability was 181.6% greater than that with the OADHPS powder.</p><p><b>CONCLUSION</b>The microspheres of water soluble drug could be prepared by using water phase replacing organic phase as poor solvent which decrease the quantity of organic solvent and benefit the environment prevention.</p>

Investigation and application of powdering technique on oily drug of the traditional Chinese medicine / 中国中药杂志

To review the development and application of powdering technique on oily drug of the traditional Chinese medicine. There have been numerous methods of powdering technique on oily drug, such as preparing complexation, microcapsule, adsorption by adsorbent, solid lipid nanoparticles, etc. And beta-Cyclodextrin complexation is the most usually operated. Powdering techniques have broad prospects in the pharmaceutical field, but more efforts should be made to improve oily drug of the traditional Chinese medicine.

Preparation of sustained-release nitrendipine microspheres with a solid dispersed structure in liquid system / 药学学报

<p><b>AIM</b>To prepare the sustained-release nitrendipine microspheres with a solid dispersed structure in liquid system.</p><p><b>METHODS</b>The sustained-release nitrendipine microspheres with a solid dispersed structure was prepared in liquid system by combining spherical crystallization technique and solvent deposition method in one step. The resultant microspheres were evaluated for the recovery, micromeritc properties, incorporation efficiency. The factors of effect on the formation and the release rate of microspheres were also investigated.</p><p><b>RESULTS</b>The recovery of microspheres (280-900 microns) was more than 70% and the bulk density was around 0.7 kg.L-1. The incorporation efficiency always exceeded 95%. The formation of microspheres was mainly affected by the amount of bridging liquid and the emulsifying agents in poor solvent. The release rate of nitrendipine from the microspheres could be controlled as desired by adjusting the ratio of talc to Eudragit RS PO in the formulation.</p><p><b>CONCLUSION</b>The presented method was suitable for preparing sustained-release microspheres of a water insoluble drug.</p>