| 摘要 |
The disclosure relates to crystalline minocycline base. In particular, three crystalline polymorphic forms, designated Form I, Form Il and Form III, of minocycline base characterised by XRD and IR data are disclosed. Processes for preparing these polymorphic forms are also disclosed. For example, Form I is prepared by dissolving and/or suspending amorphous minocycline base in an organic solvent chosen from ethers followed by crystallisation from the mixture. |
