Study On Solvatomorphism Of Ginkgolide K

This doctoral dissertation is focusing on scope of topics of drug polymorphs.And the content is divided into three chapters.In this chapter,summaries of the major theory and principles as well as applications of drug polymorphism was reported,which provided research backgrounds and basis of the topics of drug polymorphs.In-depth studies of the crystal structures were carried out,which have successfully solved difficulties in the structural elucidation such as conformation,configuration,packing arrangements,and adducted solvents.Furthermore,simulated X-ray powder diffractometric patterns were calculated with the crystallographic information files obtained,which can be made as standards of pure polymorphic substances.The polymorphs’ study of the A,B,C and the KY04 of Ginkgo biloba with the solvent evaporation method were carried out.It is found that the Ginkgo A is usually in the presence of a hydrate state,which is the raw material of the Ginkgo A.Ginkgo C is usually in the presence of a half of hydrate state There are polymorphic forms of Ginkgo B and KY04.Further to screen the polymorphs of Ginkgo B and KY04,we can find that there were four kinds of solvents of Ginkgo B,and 1 kinds of non solvent compounds were found.This study was based on the systematic screening of the compounds of Ginkgo biloba KY04 with 12 crystal forms being found.4 species have been identified,whose the absolute configuration have been done,and 1 kinds of non solvent compounds.Moreover,they are the first time to be found.We give detailed descriptions of polymorphic screenings,characterizations and evaluations with the form of solvate-free and the form with one water molecule.Methods of polymorphic characterizations in this dissertation include X-ray powder diffractometry,differential scanning calorimetry,infrared spectroscopy,etc.And the procedures of evaluation were carried out by assessing the properties of polymorphic stability and solubility.In-depth and detailed polymorphic studies of the compounds involved in this dissertation for further drug development,selective advantage polymorphs and improve the quality of generic drugs provide scientific data.