The low solubility, weak acid drug, niclosamide is a host cell modulator with broad-spectrum anti-viral cell-activity against many viruses, including stopping the SARS-CoV-2 virus from infecting cells in cell culture. As a result, a simple universal nasal spray preventative was proposed and investigated in earlier work regarding the dissolution of niclosamide into simple buffers. However, starting with pharmaceutical grade, niclosamide represents a new 505(b)(2) application. The motivation for this second paper in the series was therefore to explore if and to what extent niclosamide could be extracted from commercially available and regulatory-approved niclosamide oral tablets that could serve as a preventative nasal spray and an early treatment oral/throat spray, with possibly more expeditious testing and regulatory approval. Measurements of supernatant niclosamide concentrations were made by calibrated UV-Vis for the dissolution of niclosamide from commercially available Yomesan crushed into a powder for dissolution into Tris Buffer (TB) solutions. Parameters tested were as follows: time (0–2 days), concentration (300 µM to -1 mM), pH (7.41 to 9.35), and anhydrous/hydrated state. Optical microscopy was used to view the morphologies of the initial crushed powder, and the dissolving and equilibrating undissolved excess particles to detect morphologic changes that might occur. Concentration dependence: Niclosamide was readily extracted from powdered Yomesan at pH 9.34 TB at starting Yomesan niclosamide equivalents concentrations of 300 µM, 600 µM, and 1 mM. Peak dissolved niclosamide supernatant concentrations of 264 µM, 216 µM, and 172 µM were achieved in 1 h, 1 h, and 3 h respectively. These peaks though were followed by a reduction in supernatant concentration to an average of 112.3 µM ± 28.4 µM after overnight stir on day 2. pH dependence: For nominal pHs of 7.41, 8.35, 8.85, and 9.35, peak niclosamide concentrations were 4 µM, 22.4 µM, 96.2 µM, and 215.8 µM, respectively. Similarly, the day 2 values all reduced to 3 µM, 12.9 µM, 35.1 µM, and 112.3 µM. A heat-treatment to 200 °C dehydrated the niclosamide and showed a high 3 h concentration (262 µM) and the least day-2 reduction (to 229 µM). This indicated that the presence, or formation during exposure to buffer, of lower solubility polymorphs was responsible for the reductions in total solubilities. These morphologic changes were confirmed by optical microscopy that showed initially featureless particulate-aggregates of niclosamide could grow multiple needle-shaped crystals and form needle masses, especially in the presence of Tris-buffered sodium chloride, where new red needles were rapidly made. Scale up: A scaled-up 1 L solution of niclosamide was made achieving 165 µM supernatant niclosamide in 3 h by dissolution of just one fifth (100 mg niclosamide) of a Yomesan tablet. These comprehensive results provide a guide as to how to utilize commercially available and approved tablets of niclosamide to generate aqueous niclosamide solutions from a simple dissolution protocol. As shown here, just one 4-tablet pack of Yomesan could readily make 165 L of a 20 µM niclosamide solution giving 16,500 10 mL bottles. One million bottles, from just 60 packs of Yomesan, would provide 100 million single spray doses for distribution to mitigate a host of respiratory infections as a universal preventative-nasal and early treatment oral/throat sprays throughout the world. pH dependence of niclosamide extraction from crushed Yomesan tablet material into Tris buffer (yellow-green in vial) and Tris-buffered saline solution (orange-red in vial). Initial anhydrous dissolution concentration is reduced by overnight stirring to likely monohydrate niclosamide; and is even lower if in TBSS forming new niclosamide sodium needle crystals grown from the original particles.

中文翻译：

---

将氯硝柳胺从商业批准的片剂中提取到水性缓冲溶液中，产生潜在批准的针对 COVID-19 和其他呼吸道感染的口腔和鼻腔喷雾剂

低溶解度、弱酸性药物氯硝柳胺是一种宿主细胞调节剂，对许多病毒具有广谱抗病毒细胞活性，包括阻止 SARS-CoV-2 病毒感染细胞培养物中的细胞。因此，在早期关于将氯硝柳胺溶解到简单缓冲液中的工作中，提出并研究了一种简单的通用鼻腔喷雾预防剂。然而，从医药级开始，氯硝柳胺代表了一种新的 505(b)(2) 应用。因此，该系列的第二篇论文的动机是探讨是否以及在何种程度上可以从市售和监管部门批准的氯硝柳胺口服片剂中提取氯硝柳胺，这些片剂可用作预防性鼻腔喷雾剂和早期治疗口腔/喉咙喷雾剂，其中可能更迅速的测试和监管批准。氯硝柳胺上清液浓度的测量是通过校准的 UV-Vis 进行的，用于溶解来自市售 Yomesan 的氯硝柳胺，粉碎成粉末以溶解到 Tris 缓冲液 (TB) 溶液中。测试的参数如下：时间（0–2 天）、浓度（300 µM 至 -1 mM）、pH（7.41 至 9.35）和无水/水合状态。使用光学显微镜观察初始粉碎粉末的形态，以及溶解和平衡未溶解的过量颗粒以检测可能发生的形态变化。浓度依赖性：在 300 µM、600 µM 和 1 mM 的起始 Yomesan 氯硝柳胺等效浓度下，很容易从 pH 9.34 TB 的粉末状 Yomesan 中提取氯硝柳胺。在 1 小时、1 小时、和 3 小时。在第 2 天过夜搅拌后，这些峰之后上清液浓度降低至平均 112.3 µM ± 28.4 µM。pH 依赖性：对于 7.41、8.35、8.85 和 9.35 的标称 pH，氯硝柳胺的峰值浓度为 4 µM，分别为 22.4 µM、96.2 µM 和 215.8 µM。同样，第 2 天的值全部减少到 3 µM、12.9 µM、35.1 µM 和 112.3 µM。热处理至 200 °C 会使氯硝柳胺脱水，并显示出 3 小时的高浓度 (262 µM) 和最少的第 2 天减少量（至 229 µM）。这表明较低溶解度多晶型物的存在或在暴露于缓冲液期间的形成是总溶解度降低的原因。光学显微镜证实了这些形态变化，显示最初无特征的氯硝柳胺颗粒聚集体可以生长出多个针状晶体并形成针状团块，尤其是在存在 Tris 缓冲氯化钠的情况下，会迅速形成新的红色针状体。放大：通过仅溶解五分之一（100 mg 氯硝柳胺）的 Yomesan 片剂，在 3 小时内将氯硝柳胺放大至 1 L 溶液，达到 165 µM 上清液氯硝柳胺。这些全面的结果为如何利用市售和批准的氯硝柳胺片剂从简单的溶解方案生成氯硝柳胺水溶液提供了指导。如此处所示，仅一包 4 片 Yomesan 就可以轻松制备 165 L 的 20 µM 氯硝柳胺溶液，提供 16,500 个 10 mL 瓶。一百万瓶，仅 60 包 Yomesan，就可以提供 1 亿次单次喷雾剂量，作为一种通用的鼻腔预防和早期治疗口腔/喉咙喷雾剂，可以在全球范围内分发，以减轻大量呼吸道感染。将压碎的 Yomesan 片剂材料中的氯硝柳胺提取到 Tris 缓冲液（小瓶中的黄绿色）和 Tris 缓冲盐水溶液（小瓶中的橙红色）中的 pH 依赖性。通过过夜搅拌将初始无水溶解浓度降低至可能的一水氯硝柳胺；如果在 TBSS 中形成从原始颗粒生长的新的氯硝柳胺钠针状晶体，则甚至更低。将压碎的 Yomesan 片剂材料中的氯硝柳胺提取到 Tris 缓冲液（小瓶中的黄绿色）和 Tris 缓冲盐水溶液（小瓶中的橙红色）中的 pH 依赖性。通过过夜搅拌将初始无水溶解浓度降低至可能的一水氯硝柳胺；如果在 TBSS 中形成从原始颗粒生长的新的氯硝柳胺钠针状晶体，则甚至更低。将压碎的 Yomesan 片剂材料中的氯硝柳胺提取到 Tris 缓冲液（小瓶中的黄绿色）和 Tris 缓冲盐水溶液（小瓶中的橙红色）中的 pH 依赖性。通过过夜搅拌将初始无水溶解浓度降低至可能的一水氯硝柳胺；如果在 TBSS 中形成从原始颗粒生长的新的氯硝柳胺钠针状晶体，则甚至更低。