The present invention relates to solid forms of 13-(N-Boc- β -isobutylserinyl)-14- β -hydroxybaccatin III 1,14-carbonate (Ortataxel). Amorphous Form A, crystalline Form B, mixtures thereof and processes for preparing them are disclosed. Amorphous Form A is prepared by fast precipitation of Ortataxel from a mixture of acetone and water. Form A transforms in Form B when suspended and stirred in a mixture of ethanol and water for 4-8 hours. If the suspension is stirred for less than 4 hours, mixtures of Form B and Form A are obtained. Form B or mixtures of Forms A and B can also be obtained dissolving Ortataxel in a protic organic solvent, followed by addition of water.本發明係關於13-(N-Boc-β-異丁基絲胺酸基)-14-β-羥基巴卡丁(hydroxybaccatin)III 1,14-碳酸酯(歐塔紫杉醇(Ortataxel))的固體形式。揭示非晶形A形、晶形B形、其混合物及其製備方法。非晶形A形係藉由自丙酮與水的混合物中快速沉澱歐塔紫杉醇而製備。當於乙醇與水的混合物中懸浮及攪拌4-8小時,A形轉換成B形。如果懸浮液攪拌少於4小時,則得到B形與A形的混合物。B形或A與B形的混合物亦可藉由使歐塔紫杉醇溶解於質子性有機溶劑,接著加入水而得到。
