Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
Int J Biol Macromol. 2021 Nov 1;190:989-998. doi: 10.1016/j.ijbiomac.2021.09.074. Epub 2021 Sep 17.
The present study aimed to investigate the thermal- and pH-dependent gelation behavior of gelatin/HPMCP blends using ultraviolet (UV) spectrophotometry, viscoelasticity, and dynamic light scattering (DLS). We found that the release of lisinopril from gelatin/HPMCP gels can be inhibited at low pH. UV spectrophotometric analysis showed that pH had a significant effect on the transparency of aqueous HPMCP systems and gelatin/HPMCP gels. The viscoelastic patterns of gelatin/HPMCP at pH 4.6 considerably differed from those of gelatin/HPMCP at pH 5.2 and 6.0. DLS measurements showed that HPMCP molecules in low concentrations underwent strong aggregation below pH 4.8. Such HPMCP aggregation induces a physical barrier in the matrix structures of the gelatin/HPMCP gels, which inhibits the drug release at pH 1.2. This hydrogel delivery system using polymer blends of gelatin/HPMCP can be used in oral gel formulations with pH-responsive properties.
本研究旨在使用紫外（UV）分光光度法、粘弹性和动态光散射（DLS）研究明胶/HPMCP 共混物的热和 pH 值依赖性凝胶行为。我们发现，在低 pH 值下，可以抑制依普利酮从明胶/HPMCP 凝胶中的释放。UV 分光光度分析表明，pH 值对 HPMCP 水溶液系统和明胶/HPMCP 凝胶的透明度有显著影响。在 pH 4.6 时，明胶/HPMCP 的粘弹性模式与在 pH 5.2 和 6.0 时的粘弹性模式有很大的不同。DLS 测量表明，低浓度的 HPMCP 分子在 pH 值低于 4.8 时会发生强烈聚集。这种 HPMCP 聚集在明胶/HPMCP 凝胶的基质结构中形成物理屏障，从而抑制了在 pH 值 1.2 时的药物释放。这种使用明胶/HPMCP 聚合物共混物的水凝胶给药系统可用于具有 pH 响应特性的口服凝胶制剂。
