Micronization of phenylbutazone by rapid expansion of supercritical CO2 solution.

Rapid expansion of supercritical solutions (RESS) technique was applied for the preparation of phenylbutazone fine particles. The operating temperature and pressure affected the yield of the drug fine particles, which was evaluated by dissolving the sprayed product of drug into ethanol. Effect of pre- and post-expansion conditions on the particle size distribution of phenylbutazone was investigated and the smallest sample (mean particle size: 1.59 microm) was obtained when the RESS method was operated at a pressure of 26 MPa combined with a temperature of 32 degrees C. Physicochemical properties of the fine particles were investigated by powder X-ray diffraction and differential scanning calorimetry. It was found that the phenylbutazone fine particles obtained were meta-stable beta form under the experimental conditions tested, suggesting polymorphic transformation during the RESS process.

Gluco-indole alkaloids from Nauclea cadamba in Thailand and transformation of 3 alpha-dihydrocadambine into the indolopyridine alkaloid, 16-carbomethoxynaufoline.

Three monoterpenoid gluco-indole alkaloids, 3beta-isodihydrocadambine, cadambine, and 3alpha-dihydrocadambine, were isolated from Nauclea cadamba ROXB. growing in Thailand. The stereochemistry at C19 in 3beta-isodihydrocadambine was elucidated to be R by spectroscopic analysis. Treatment of 3alpha-dihydrocadambine with beta-glucosidase in aqueous ammonium acetate solution gave an indolopyridine alkaloid, 16-carbomethoxynaufoline, and an unusually rearranged compound.