Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Torino, Italy.
Molecules. 2021 Apr 25;26(9):2500. doi: 10.3390/molecules26092500.
Piroxicam (PRX) is a commonly prescribed nonsteroidal anti-inflammatory drug. Its efficacy, however, is partially limited by its low water solubility. In recent years, different studies have tackled this problem and have suggested delivering PRX through solid dispersions. All these strategies, however, involve the use of potentially harmful solvents for the loading procedure. Since piroxicam is soluble in supercritical CO (scCO), the present study aims, for the first time, to adsorb PRX onto mesoporous silica using scCO, which is known to be a safer and greener technique compared to the organic solvent-based ones. For comparison, PRX is also loaded by adsorption from solution and incipient wetness impregnation using ethanol as solvent. Two different commercial mesoporous silicas are used (SBA-15 and Grace Syloid XDP), which differ in porosity order and surface silanol population. Physico-chemical analyses show that the most promising results are obtained through scCO, which yields the amorphization of PRX, whereas some crystallization occurs in the case of adsorption from solution and IWI. The highest loading of PRX by scCO is obtained in SBA-15 (15 wt.%), where molecule distribution appears homogeneous, with very limited pore blocking.
吡罗昔康（PRX）是一种常用的非甾体抗炎药。然而，其疗效部分受到低水溶性的限制。近年来，不同的研究已经解决了这个问题，并提出通过固体分散体来输送 PRX。然而，所有这些策略都涉及到使用潜在有害的溶剂进行负载过程。由于吡罗昔康可溶于超临界 CO（scCO）中，因此本研究首次旨在使用 scCO 将 PRX 吸附到介孔硅上，与基于有机溶剂的方法相比，scCO 被认为是一种更安全、更环保的技术。为了进行比较，还通过吸附从溶液和初始湿浸渍用乙醇作为溶剂来负载 PRX。使用了两种不同的商业介孔硅（SBA-15 和 Grace Syloid XDP），它们在孔隙度顺序和表面硅醇密度方面有所不同。物理化学分析表明，通过 scCO 获得了最有希望的结果，它导致 PRX 的非晶化，而在从溶液吸附和 IWI 的情况下则发生一些结晶。通过 scCO 获得的 PRX 的最高负载量是在 SBA-15 中获得的（15wt.%），其中分子分布看起来均匀，孔阻塞非常有限。
