Akinjole Omowumi, Honaryar Houman, Coulibaly Fohona S, Niroobakhsh Zahra, Youan Bi-Botti C
Laboratory of Future Nanomedicines and Theoretical Chronopharmaceutics, Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri - Kansas City, 2464 Charlotte, Kansas City 64108, MO, USA.
School of Computing and Engineering, University of Missouri - Kansas City, 5100 Rockhill Road, Kansas City 64110, MO, USA.
Int J Pharm. 2022 Oct 15;626:122070. doi: 10.1016/j.ijpharm.2022.122070. Epub 2022 Aug 28.
This study aims to characterize the rheological behavior of a novel phenylboronic acid (PBA)-based closomer nanoconjugate (Closogel) with potential application in pharmaceutical formulation. PBA was used as a cross-linking agent and model (antiviral) drug. The PBA loaded Closogel chemical structure was analyzed by boron (B) NMR and Fourier transform infrared (FTIR) spectroscopy. The Closogel and control hydroxyethyl cellulose (HEC) gel were analyzed under oscillatory and continuous shear rheometry followed by mathematical modeling to characterize the gel flow behavior. The chemical analysis confirmed the existence of characteristic borate esters peaks and Boron chemical shifts within Closogel spectra. Due to its more flexible molecular structure, undiluted Closogel exhibited lower, yield stress, viscosity and relaxation time (30 Pa &163 Pa.s & 0.21 s vs 45 Pa &301 Pa.s & 0.39 s for HEC). Both Closogel and HEC gels exhibited a thixotropic behavior. The plastic undiluted and pseudoplastic 2.5 % w/v aqueous Closogels were more viscous than elastic (tan (δ) > 1) in the linear viscoelastic range. The Herschel-Bulkley model showed a significant fitting to all experimental data (R > 0.95). The 0.25 % w/v aqueous Closogel nearly exhibited a Newtonian behavior with a flow index of 0.93. These data suggest that PBA loaded Closomer-based gels have similar rheological behavior, with lower complex modulus than that of HEC gels, and they can be a promising platform used for delivery of topical antiviral or other bioactive agents.
本研究旨在表征一种新型基于苯基硼酸（PBA）的封闭体纳米共轭物（Closogel）的流变行为，该共轭物在药物制剂中具有潜在应用。PBA用作交联剂和模型（抗病毒）药物。通过硼（B）核磁共振（NMR）和傅里叶变换红外（FTIR）光谱对负载PBA的Closogel化学结构进行了分析。在振荡和连续剪切流变测定法下对Closogel和对照羟乙基纤维素（HEC）凝胶进行分析，随后进行数学建模以表征凝胶的流动行为。化学分析证实了Closogel光谱中存在特征性硼酸酯峰和硼化学位移。由于其分子结构更灵活，未稀释的Closogel表现出更低的屈服应力、粘度和松弛时间（分别为30 Pa、163 Pa·s和0.21 s，而HEC分别为45 Pa、301 Pa·s和0.39 s）。Closogel和HEC凝胶均表现出触变行为。在线性粘弹性范围内，未稀释的塑性和2.5% w/v的假塑性水性Closogel的粘性大于弹性（损耗角正切（tan(δ)）>1）。赫谢尔-布尔克利模型对所有实验数据显示出显著拟合（R>0.95）。0.25% w/v的水性Closogel几乎表现出牛顿行为，流动指数为0.93。这些数据表明，负载PBA的基于封闭体的凝胶具有相似的流变行为，其复数模量低于HEC凝胶，并且它们可能是用于局部递送抗病毒或其他生物活性剂的有前景的平台。
