Ensuring the photostability of sunscreen lotions is crucial for their effectiveness and safety when exposed to sunlight. Photostability refers to the ability of a substance to remain stable and undergo minimal chemical degradation or photochemical reactions upon exposure to ultraviolet (UV) radiation, especially from sunlight. In this study, we focused on 2-phenylbenzimidazole-5-sulfonic acid (PBS), one of the leading sunscreen agents, and aimed to form inclusion complexes (IC) with methyl-β-cyclodextrin (MCD). Through phase solubility measurements, we determined the stoichiometry of the IC to be 1:1, with a binding constant of 155.4 M. Proton Nuclear Magnetic Resonance (H NMR) and ROESY analysis provided evidence that the benzimidazole part of PBS is successfully included in the cavity of MCD. Quantum mechanical calculations using the B3LYP/6-31G(D, P) method in the Gaussian 16 package further supported the formation of the IC by providing energy data. Notably, the photostability of the IC is maintained for up to four hours of UV exposure, showing no significant structural changes in PBS. Moreover, we conducted biocompatibility tests, and the results are encouraging for the superior activity, and suggest the potential of the IC for promoting its cosmetic application as a UVB sunscreen.

中文翻译：

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2-苯基苯并咪唑-5-磺酸与甲基-β-环糊精防晒配方的增强光稳定性和生物相容性


确保防晒乳液的光稳定性对于其暴露在阳光下时的有效性和安全性至关重要。光稳定性是指物质在暴露于紫外线（UV）辐射（尤其是阳光）时保持稳定并发生最小化学降解或光化学反应的能力。在这项研究中，我们重点关注领先的防晒剂之一 2-苯基苯并咪唑-5-磺酸 (PBS)，旨在与甲基-β-环糊精 (MCD) 形成包合物 (IC)。通过相溶解度测量，我们确定 IC 的化学计量为 1:1，结合常数为 155.4 M。质子核磁共振 (H NMR) 和 ROESY 分析证明 PBS 的苯并咪唑部分已成功包含在MCD 腔。使用Gaussian 16包中的B3LYP/6-31G(D, P)方法进行的量子力学计算通过提供能量数据进一步支持IC的形成。值得注意的是，在长达四个小时的紫外线照射下，IC 的光稳定性仍保持不变，表明 PBS 中没有显着的结构变化。此外，我们还进行了生物相容性测试，其优异的活性结果令人鼓舞，并表明 IC 作为 UVB 防晒霜具有促进其化妆品应用的潜力。