The purpose of the work was to develop such chromatographic conditions that allowed to separate as many naproxen degradation products as possible. In order to follow this process, thin-layer chromatography (TLC) coupled with densitometry and spectrodensitometry was used. A forced degradation study was performed using an ethanolic solution of naproxen spotted on silica gel plates, existing in the form of an aqueous solution at various pH values, and as solution prepared in saline and in hydrogen peroxide. Degradative effect of UV light on naproxen was watched in the context of naproxen spotted on plates precoated with silica gel and exposed to UV light, and also for its solution treated with UV light. However, the solution of naproxen prepared in water at pH ≈ 2.60 undergoes the largest changes as the results of its exposure to UV light during 10 h. Stressed samples of naproxen were analyzed by using a new and well validated TLC procedure including toluene (TOL)—acetone (ACE)—chloroform (CHL) (2:5:12, v/v/v) as mobile phase A and glacial acetic acid (AcOH)—n-hexane (Hex)—acetone (ACE)-(0.10:10:10, v/v/v) as mobile phase B. As the newly developed TLC-densitometric method can effectively separate the substances about pharmaceutical significance from products of its degradation, which are formed as a result of stress studies, is considered to be a good alternative and important tool in routine quality control and stability testing of naproxen in pharmaceutical formulations. These results indicate that proposed TLC-densitometric method is cost-effective, rapid, specific, accurate, and precise. This TLC procedure is comparable to HPLC and UPLC method in terms of detection the number of degradation products of naproxen. In addition, it realizes the criterion of linearity. A major advantage and novelty of proposed method is its low cost and ability to analyze examined drug and all degradation products simultaneously, including those which can be observed under intensive UV radiation exposure of naproxen solution which are not described by previous HPTLC studies available in the literature.

中文翻译：

---

快速TLC和光度法评估萘普生的稳定性

这项工作的目的是开发这样的色谱条件，以允许分离尽可能多的萘普生降解产物。为了遵循此过程，使用了结合了光密度法和光密度法的薄层色谱（TLC）。使用萘普生的乙醇溶液点样在硅胶板上进行强制降解研究，萘普生的乙醇溶液以各种pH值的水溶液形式存在，并且是在盐水和过氧化氢中制备的溶液。观察到萘普生在预先涂有硅胶并暴露于紫外光的板上点缀萘普生的情况，还观察了其对萘普生的降解作用，并观察了其溶液是否经过紫外光处理。但是，萘普生在pH≈2.60的水中制备的溶液发生最大的变化，这是由于萘普生在10 h内暴露于紫外线。ñ-己烷（Hex）-丙酮（ACE）-（0.10：10：10，v / v / v）作为流动相B。由于新开发的TLC密度测定法可以有效地将具有重要化学意义的物质与其降解产物分离由于压力研究的结果而形成，被认为是常规制剂制剂中萘普生的质量控制和稳定性测试的良好替代和重要工具。这些结果表明，提出的TLC密度法是经济有效，快速，专一，准确和精确的。在检测萘普生降解产物的数量方面，该TLC程序可与HPLC和UPLC方法相媲美。另外，它实现了线性标准。