Faculty of Pharmaceutical Sciences, University of Iceland, Hofsvallagata 53, 107 Reykjavik, Iceland; Oculis ehf, Alfheimar 74, 6th Floor, 104 Reykjavik, Iceland.
Oculis ehf, Alfheimar 74, 6th Floor, 104 Reykjavik, Iceland; Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, 254 Phyathai Road, Wangmai, Pathumwan, Bangkok 10330, Thailand.
Int J Pharm. 2020 Jul 30;585:119452. doi: 10.1016/j.ijpharm.2020.119452. Epub 2020 May 25.
Dexamethasone release from natural γ-cyclodextrin (γCD) complexes was investigated in presence of porcine pancreatic α-amylase (PPA). The phase-solubility of dexamethasone in aqueous γCD solutions was determined, PPA degradation of γCD was investigated, and permeation studies were performed in simulated tear fluid. The phase-solubility profile was of B type and the stability constant (K) of the dexamethasone/γCD complex determined from the initial linear section of the profile was relatively high or 12887 M. The high K value indicates that dexamethasone has high affinity for γCD under the test condition. From the PPA catalyzed γCD degradation studies the Michaelis-Menten constant (K) and V were determined to be 3.24 mM and 9.79 × 10 mM/min, respectively. The permeation studies performed at low γCD concentrations, showed that dexamethasone is released from the complex solutions at faster rate when PPA was present than when no PPA was present.
研究了在猪胰腺α-淀粉酶（PPA）存在下，地塞米松从天然γ-环糊精（γCD）复合物中的释放情况。测定了地塞米松在水合γCD 溶液中的相溶解度，研究了 PPA 对 γCD 的降解作用，并在模拟泪液中进行了渗透研究。相溶解度曲线为 B 型，从曲线初始线性段确定的地塞米松/γCD 复合物的稳定常数（K）相对较高，为 12887 M。高 K 值表明，在测试条件下，地塞米松与 γCD 具有高亲和力。从 PPA 催化的 γCD 降解研究中，确定了米氏常数（K）和 V 分别为 3.24 mM 和 9.79×10 mM/min。在低 γCD 浓度下进行的渗透研究表明，当存在 PPA 时，地塞米松从复合物溶液中的释放速度比不存在 PPA 时快。
