The interaction of Methyl Cellulose (MC) with amino acid-based anionic surfactants viz. sodium lauryl sarcosinate (SLS) and sodium stearyl sarcosinate (SSS) having different hydrophobic chain lengths but the same head group has been investigated using surface tension, rheological and UV–Vis spectrophotometric measurements. The effect of poorly water-soluble drug Rifampicin (Rif) on the physicochemical and rheological properties of the MC-surfactant system was also elucidated. The tensiometric profiles of the two systems (MC + SLS & MC + SSS) indicated that the Critical Aggregation Concentrations (CACs) are further reduced in presence of Rif while as the Critical Micelle Concentrations (CMCs) remain more or less constant. The oscillatory rheological experiments revealed that the gelation is highly dependent upon the applied frequency and concentration of the surfactants. Moreover, the viscoelasticity of the polymer-surfactant system is greatly modulated by the presence of Rif molecules which tend to decrease the viscoelasticity of the MC + SSS system more than that of MC + SLS system till the CAC. The kinetic stability of Rif w.r.t. oxidation with H₂O₂ in MC and MC-surfactant systems revealed that the polymer-surfactant systems were able to stabilize and protect the drug more than individual polymer or surfactant systems. The systems were also investigated for drug (Rif) release at pHs 7.4 and 4.0 in which diffusion predominant release was observed at pH 7.4 while at pH 4.0, the release was controlled by both diffusion and relaxation phenomenon. These experimental findings could be important for modulating the use of polymer-surfactant systems for enhancing the drug stability and their application in pH-responsive drug release.

甲基纤维素（MC）与基于氨基酸的阴离子表面活性剂的相互作用。月桂基肌氨酸钠（SLS）和硬脂基肌氨酸钠（SSS）具有不同的疏水链长度，但相同的头基已通过表面张力，流变学和UV-Vis分光光度法进行了研究。还阐明了水溶性差的药物利福平（Rif）对MC表面活性剂系统的理化性质和流变性质的影响。两种系统（MC + SLS和MC + SSS）的张力分布图表明，在Rif的存在下，临界聚集浓度（CAC）进一步降低，而临界胶束浓度（CMC）保持恒定。振荡流变实验表明，凝胶化高度依赖于表面活性剂的施加频率和浓度。此外，Rif分子的存在极大地调节了聚合物-表面活性剂系统的粘弹性，与在CAC之前相比，Rif分子比MC + SLS系统的粘弹性更倾向于降低MC + SSS系统的粘弹性。Rif wrt被H氧化的动力学稳定性MC和MC表面活性剂体系中的₂ O ₂表明，聚合物表面活性剂体系比单独的聚合物或表面活性剂体系更能稳定和保护药物。还研究了系统在pH 7.4和4.0下的药物（Rif）释放，其中在pH 7.4处观察到扩散为主释放，而在pH 4.0时，释放受扩散和松弛现象控制。这些实验结果对于调节聚合物表面活性剂系统的使用以增强药物稳定性及其在pH响应药物释放中的应用可能是重要的。