University Institute of Pharmaceutical Sciences, UGC-Centre of Advanced Studies (CAS), Panjab University, Chandigarh 160 014, India.
University Institute of Pharmaceutical Sciences, UGC-Centre of Advanced Studies (CAS), Panjab University, Chandigarh 160 014, India.
J Pharm Biomed Anal. 2018 May 10;153:102-109. doi: 10.1016/j.jpba.2018.02.006. Epub 2018 Feb 8.
The present work highlights a novel polymorph (form II) of ambrisentan (AMT), a selective endothelin type A (ETA) receptor antagonist used in the treatment of pulmonary arterial hypertension (PAH). Form II was isolated by solution crystallization and characterised by differential scanning calorimetry, powder X-ray diffraction, solution calorimetry and aqueous solubility. The single crystal X-ray diffraction shows that it crystallizes in monoclinic system with space group P21/c different from the form I (commercial form). Form II was found to be enantiotropically related to form I. Apparent solubility of form II was performed in 0.1 N HCl (pH 1.2) was found to be higher (1.5 fold) than of form I. Solution mediated and stress-induced phase transformation studies revealed conversion of form II to form I. Accelerated stability studies (40 °C & 75% RH) also reveal that form II converted to form I after one month. However, this does not belittle the improved solubility of a new solid form.
本工作重点介绍了一种新型的安立生坦(AMT)多晶型物(II 型),AMT 是一种选择性内皮素 A(ETA)受体拮抗剂,用于治疗肺动脉高压(PAH)。II 型是通过溶液结晶法分离得到的,并通过差示扫描量热法、粉末 X 射线衍射、溶液量热法和水溶解度进行了表征。单晶 X 射线衍射表明,它结晶为单斜晶系,空间群为 P21/c,与 I 型(商业形式)不同。II 型被发现与 I 型具有假各向同性关系。在 0.1N HCl(pH1.2)中进行的 II 型的表观溶解度研究表明,其溶解度比 I 型高(1.5 倍)。溶液介导和应激诱导的相转变研究表明,II 型向 I 型转化。加速稳定性研究(40°C 和 75%RH)也表明,II 型在一个月后转化为 I 型。然而,这并没有贬低新固体形式的提高的溶解度。