A novel isocratic stability-indicating chromatographic method was developed, optimized and validated using Design-Expert® following ICH guidelines for the quantification of Timolol maleate (TM). The intrinsic stability of TM was assessed by force degradation studies, which concluded no extensive degradation except under alkaline and oxidative conditions. TM was quantified accurately in the surfactant-based elastic vesicular system by separating it on Hypersil BDS C8 column using triethylamine in H2O (0.15%v/v; pH 3.0) and acetonitrile (ACN; 65:35%v/v). The influence of variable factors like mobile phase pH, injection volume (μL), flow rate (mL/min) and ACN content (%) on method responses were assessed using a full factorial design. The method was linear between 0.05 and 10 μg/mL with an R2 value of 0.9993. Limit of detection and limit of quantification were found to be 0.90 and 27.2 ng/mL. The method was specific, with recovery in plain drug solution of 89–92% and elastic nanovesicles of 90–93%. The experimental model was significant (P < 0.0001) as indicated by deliberate changes in the method analyzed through analysis of variance. The total drug content in elastic nanovesicles was estimated to be 9.53 ± 0.01 mg/20-mL dispersion and entrapment efficiency was 44.52 ± 0.73%. The developed method was rapid, economic and precise for the quantification of TM in bulk and vesicular system.

中文翻译：

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用于开发和验证基于表面活性剂的弹性纳米囊泡系统中马来酸噻吗洛尔估计稳定性的 RP-HPLC 方法的全因子设计

遵循 ICH 马来酸噻吗洛尔 (TM) 定量指南，使用 Design-Expert® 开发、优化和验证了一种新颖的等度稳定性指示色谱方法。通过力降解研究评估了 TM 的内在稳定性，该研究得出结论，除了在碱性和氧化条件下，没有广泛的降解。在基于表面活性剂的弹性囊泡系统中，通过使用三乙胺在 H2O（0.15%v/v；pH 3.0）和乙腈（ACN；65:35%v/v）中的溶液在 Hypersil BDS C8 柱上对其进行分离，从而准确量化了 TM。使用全因子设计评估了流动相 pH、进样量 (μL)、流速 (mL/min) 和 ACN 含量 (%) 等可变因素对方法响应的影响。该方法在 0.05 和 10 μg/mL 之间呈线性，R2 值为 0.9993。检测限和定量限分别为 0.90 和 27.2 ng/mL。该方法具有特异性，在普通药物溶液中的回收率为 89-92%，弹性纳米囊泡的回收率为 90-93%。实验模型是显着的（P < 0.0001），如通过方差分析分析的方法的故意变化所示。弹性纳米囊泡中的总药物含量估计为 9.53 ± 0.01 mg/20-mL 分散体，包封率为 44.52 ± 0.73%。所开发的方法快速、经济和精确地定量散装和囊泡系统中的 TM。0001），如通过方差分析分析的方法的故意变化所表明的。弹性纳米囊泡中的总药物含量估计为 9.53 ± 0.01 mg/20-mL 分散体，包封率为 44.52 ± 0.73%。所开发的方法快速、经济和精确地定量散装和囊泡系统中的 TM。0001），如通过方差分析分析的方法的故意变化所表明的。弹性纳米囊泡中的总药物含量估计为 9.53 ± 0.01 mg/20-mL 分散体，包封率为 44.52 ± 0.73%。所开发的方法快速、经济和精确地定量散装和囊泡系统中的 TM。