Preparation of polymeric nanoparticles of cyclosporin A using infrared pulsed laser.

Nanoparticle formation of poorly water-soluble drugs is a means of providing much benefit for improving solubility and bioavailability. We showed that laser irradiation of drugs can be a novel tool for dispersing drug nanoparticles in water. Using our method, we were able to produce nanoparticles containing immunosuppressant drug, cyclosporin A, which shows poor solubility toward water, with high levels of the drug using polyvinyl pyrrolidone and sodium dodecyl sulfate as stabilizing agents. The absence of degradation products was confirmed and the loss of pharmaceutical activity with an inhibitory effect on the interleukin-2 production of Jurkat T cells did not occur. Cyclosporin A nanoparticles showed a spherical shape and their particle size was distributed uniformly around 200 nm. Powder X-ray diffraction analysis suggested that cyclosporin A in the nanoparticles was in an amorphous state. In the measurement of solubility rate, the nanoparticle formulation showed a higher rate than that which had not been processed. At present, although this laser irradiation technology has low productivity, it is expected as a new technology for drug nanoparticle manufacturing together with the development of a new laser device.