| The particle size and polymorph of poor water-soluble drugs have significant influence on the solubility. The physicochemical and biochemical properties, such as stability, bioavailability and antitumor, are also effected by polymorph. In order to solve the undesired solubility problems of drugs, the one step supercritical anti-solvent(SAS) process seems preferable to producing fine particles of a pure polymorph, which with low solvent residue and desired properties. In this thesis, the 9-nitro-camptothecin(9-NC) and Gefitinib were selected to study the effects of SAS process parameters on properties of particles.The supercritical carbon dioxide and a variety of organic solvents were chose as the anti-solvent and solvent system, respectively. And, the orthogonal experiment and single factor experiment were applied for 9-NC and Gefitinib. Samples were characterized using laser diffraction particle size analysis, FT-IR, GC, SEM, XRD, DSC and TGA. The effects of process parameters, including the solvent system(S), the concentration of the solution(C), the flow rate of solution(F), the precipitation pressure(P) and temperature(T) on the properties of drugs were investigated.The results showed that new polymorphic forms of 9-NC and Gefitinib were generated after the SAS process, and the selected organic solvent system has bigger influence on the crystal structure transformation. According to the orthogonal array design, it can be found that the influence of the five parameters on Dp50 of 9-NC is F > S > T > C > P. According to the single factor experiment of Gefitinib, Particle size increases with the increase of the solution flow rate and the concentration, decrease of operating pressure. And along with the rise of temperature, the particle size decrease first and then increase.The results of this thesis have great guiding significance for controllable preparation of nano-polymorphs of 9-NC and Gefitinib. |
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