BACKGROUND: As Resina Draconis is water insoluble, it is difficult to be made into injection. Meanwhile, the oral preparation and enemas of Resina Draconis, due to the water insolubility and large particle size, have poor in vivo absorption and very low bioavailability. Polymeric hollow nanoparticles have large surface area and strong adsorption characteristics; moreover, the hollow core parts can accommodate a large number of guest molecules. Therefore, the hollow nanoparticles have a series of peculiar properties based on the microcapsule effect.
OBJECTIVE: To review the literatures covering the preparation methods and in vitro release researches on Resina Draconis-loaded biodegradable polymeric hollow nanoparticles.
METHODS: A computer-based search was performed in PubMed database, Chinese Science and Technology Periodical Database (1989 to 2014), China Academic Conference Papers Database (1986 to 2014), Chinese Dissertations Database (1986 to 2014), China Patent Database (1985 to 2014), Chinese Science and Technology Paper and Citation Database (1999 to 2014), China Journal Full Text Database (1979 to 2014), China Outstanding Master's Degree Thesis Database (1999 to 2014), Chinese Doctoral Dissertations Full Text Database (1999 to 2014) for relevant articles by the retrieval key words of “resina draconis, nanoparticles, hollow particles, biodegradable polymer” in English and Chinese, respectively.
RESULTS AND CONCLUSION: The traditional Chinese medicine Resina Draconis is firstly dissolved in suitable solvents like ethanol, isopropanol or solvents, forming nearly saturated solution. Then the pre-made polymer hollow nanoparticles are dispersed in the solution, with ultrasonic oscillation for a certain time. After separation by high-speed centrifugation, Resina Draconis-loaded nanoparticles can be prepared successfully. It is of great importance to make the Chinese medicine Resina Draconis into microemulsion nanoparticles, forming “homogeneous solution” in the medium of water, which will lead to the remarkable improvement of the in vivo absorbability and bioavailability of Resina Draconis. Furthermore, the sustainable release of microemulsion contributes to little adverse reaction, low dosage, long duration, etc. Consequently, the Resina Draconis-loaded nanoparticle emulsion is expected to be made into powder, tablet, ointment, capsule, even injection or some other dosage forms. The nano-scale emulsion of Resina Draconis is expected to be injected intravenously, which will directly reach the focus through the blood circulation to cure blood stasis, cardiovascular and cerebrovascular diseases. In addition, the release rate of loaded drugs can be controlled by means of regulating the thickness and porosity of hollow nanoparticle shells, and by surface modification with biological chemicals, the drug-loaded nanoparticles are expected to possess targeting characteristics.