作者希望感谢美国国立卫生研究院（R01AI155922）的资助。显微镜在教堂山分析和纳米制造实验室 （CHANL） 进行，该实验室是北卡罗来纳州三角研究纳米技术网络 RTNN 的成员，该网络由美国国家科学基金会 Grant ECCS-1542015 支持，作为国家纳米技术协调基础设施 NNCI 的一部分。

所有动物实验均按照《动物福利法》和《关于人道护理和使用实验动物的公共卫生服务政策》进行。该研究方案已获得田纳西大学健康科学中心机构动物护理和使用委员会的批准。~6-8周龄的健康雌性BALB / c小鼠通过肺内气溶胶递送给予一种给药剂的干粉含量，以使用大观霉酰胺1599干粉进行药代动力学研究9。这些动物是从商业来源获得的（见 材料表）。
1. 配料器和灌装组件的准备
<ol><li>使用精密切片锯（参见材料表）或皮带砂光机修剪 2.54 厘米（1 英寸）钝不锈钢针 （21-25 G） 的塑料鲁尔部分，直到 2-3 毫米的塑料鲁尔剩余（图 1A 和图 2A）。 注意： 如果使用带式砂光机，可能需要使用较小的针或金属丝清洁不锈钢针，以清除可能产生的障碍物。</li>
	<li>切掉 0.6 mL 锥形离心管的尖端 （1-1.5 cm）。用 30-35 毫克粉末填充管尖。 注：有关本研究使用的示例粉末的详细信息，请参阅代表性结果。在用于本应用之前，应按照 USP 通则第 <601 章>中描述的标准方法评估粉末气溶胶性能（参见 材料表）。</li>
	<li>如果储存和/或运输粉末，请使用管盖（切断）关闭小瓶。在储存和/或运输时，用石蜡膜密封，以尽量减少粉末暴露于环境湿气。</li>
</ol>2. 装药和组装加药器
<ol><li>根据需要多次将修剪好的不锈钢针头夯实到0.6mL锥形离心管尖端的粉末床中，以达到所需剂量（图2B）。用低绒擦拭器轻轻擦拭不锈钢针的侧面，以去除多余的粉末（图 3）。</li>
	<li>轻轻地将加载的不锈钢针插入 3.81 厘米（1.5 英寸）聚丙烯或 5.08 厘米（2 英寸）聚四氟乙烯 （PTFE） 针（16-20 G）（参见 材料表）以避免任何粉末脱落（图 1B、C 和 图 2C）。</li>
</ol>3. 驱动加药器
<ol><li>将一次性注射器回拉至所需体积，该体积可能因应用而异。 注意：对于小鼠的肺内给药，0.15-0.6 mL 通常是合适的 8,9。</li>
	<li>将注射器连接到聚丙烯或PTFE针头上的鲁尔锁上（图2D）。</li>
	<li>将加药器的针端插入所需的目标中。为了分析粉末含量和重现性，将针头穿过穿孔的橡胶隔膜或石蜡膜插入含有少量（例如，1-5 mL）水和/或有机溶剂（例如乙醇）的小瓶中，溶剂特性和体积取决于活性药物成分（API）的物理特性和定量方法。<ol><li>为了给小鼠递送，按照既定的方案9,15将针头插入麻醉小鼠气管的第一个支气管分叉处。</li>
	</ol></li>
	<li>用力按下注射器，将粉末从设备中排出到收集瓶中（图2E）。 注意：将粉末输送到小鼠肺部必须遵循相同的技术。</li>
	<li>为了分析收集瓶的内容物和重现性，请对特定 API 使用适当的分析方法，例如紫外可见光 （UV-Vis） 分光光度法或高效液相色谱 （HPLC）。</li>
</ol>

Customizable Disposable Dosators to Deliver Dry Powder Aerosol Drugs to Mice

<ol>
	<li>Wu, X., Li, X., Mansour, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+analytical+techniques+in+solid-state+particle+characterization+for+predicting+performance+in+dry+powder+inhalers.">Surface analytical techniques in solid-state particle characterization for predicting performance in dry powder inhalers.</a> KONA Powder and Particle Journal. 28, 3-18 (2010).</li><li>Maloney, S. E., Mecham, J. B., Hickey, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performance+testing+for+dry+powder+inhaler+products:+towards+clinical+relevance.">Performance testing for dry powder inhaler products: towards clinical relevance.</a> KONA Powder and Particle Journal. 40, 172-185 (2023).</li><li>Maloney, S. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spray+dried+tigecycline+dry+powder+aerosols+for+the+treatment+of+nontuberculous+mycobacterial+pulmonary+infections.">Spray dried tigecycline dry powder aerosols for the treatment of nontuberculous mycobacterial pulmonary infections.</a> Tuberculosis. 139, 102306 (2023).</li><li>Kaur, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+hand-held+apparatus+for+&amp;#34;nose-only&amp;#34;+exposure+of+mice+to+inhalable+microparticles+as+a+dry+powder+inhalation+targeting+lung+and+airway+macrophages.">A hand-held apparatus for &amp;#34;nose-only&amp;#34; exposure of mice to inhalable microparticles as a dry powder inhalation targeting lung and airway macrophages.</a> European Journal of Pharmaceutical Sciences. 34 (1), 56-65 (2008).</li><li>Yi, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole-body+nanoparticle+aerosol+inhalation+exposures.">Whole-body nanoparticle aerosol inhalation exposures.</a> Journal of Visualized Experiments. (75), e50263 (2013).</li><li>Chung, Y. H., Han, J. H., Lee, Y. -. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+study+on+subchronic+inhalation+toxicology+of+1-chloropropane.">A study on subchronic inhalation toxicology of 1-chloropropane.</a> Toxicological Research. 31 (4), 393-402 (2015).</li><li>Kuehl, P. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regional+particle+size+dependent+deposition+of+inhaled+aerosols+in+rats+and+mice.">Regional particle size dependent deposition of inhaled aerosols in rats and mice.</a> Inhalation Toxicology. 24 (1), 27-35 (2012).</li><li>Manser, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+considerations+for+intratracheal+delivery+devices+to+achieve+proof-of-concept+dry+powder+biopharmaceutical+delivery+in+mice.">Design considerations for intratracheal delivery devices to achieve proof-of-concept dry powder biopharmaceutical delivery in mice.</a> Pharmaceutical Research. 40, 1165-1176 (2023).</li><li>Stewart, I. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+characterization+of+a+dry+powder+formulation+for+anti-tuberculosis+drug+spectinamide+1599.">Development and characterization of a dry powder formulation for anti-tuberculosis drug spectinamide 1599.</a> Pharmaceutical Research. 36 (9), 136 (2019).</li><li>Durham, P. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disposable+dosators+for+pulmonary+insufflation+of+therapeutic+agents+to+small+animals.">Disposable dosators for pulmonary insufflation of therapeutic agents to small animals.</a> Journal of Visualized Experiments. (121), e55356 (2017).</li><li>Miwata, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intratracheal+administration+of+siRNA+dry+powder+targeting+vascular+endothelial+growth+factor+inhibits+lung+tumor+growth+in+mice.">Intratracheal administration of siRNA dry powder targeting vascular endothelial growth factor inhibits lung tumor growth in mice.</a> Molecular Therapy: Nucleic Acids. 12, 698-706 (2018).</li><li>Duret, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharmacokinetic+evaulation+in+mice+of+amorphous+itraconazole-based+dry+powder+formulations+for+inhalation+with+high+bioavailability+and+extended+lung+retention.">Pharmacokinetic evaulation in mice of amorphous itraconazole-based dry powder formulations for inhalation with high bioavailability and extended lung retention.</a> European Journal of Pharmaceutics and Biopharmaceutics. 86 (1), 46-54 (2014).</li><li>Maloney, S. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+strategies+of+the+anti-mycobacterial+drug+bedaquiline+for+intrapulmonary+routes+of+administration.">Preparation strategies of the anti-mycobacterial drug bedaquiline for intrapulmonary routes of administration.</a> Pharmaceuticals. 16 (5), 729 (2023).</li><li>Price, D. N., Kunda, N. K., Muttil, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Challenges+associated+with+the+pulmonary+delivery+of+therapeutic+dry+powders+for+preclinical+testing.">Challenges associated with the pulmonary delivery of therapeutic dry powders for preclinical testing.</a> KONA Powder and Particle Journal. 36, 129-144 (2019).</li><li>Qiu, Y., Liao, Q., Chow, M. Y. T., Lam, J. K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intratracheal+administration+of+dry+powder+formulation+in+mice.">Intratracheal administration of dry powder formulation in mice.</a> Journal of Visualized Experiments. (161), e61469 (2020).</li><li>Fiegel, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+in+vivo+evaluation+of+a+dry+powder+for+inhalation+of+capreomycin.">Preparation and in vivo evaluation of a dry powder for inhalation of capreomycin.</a> Pharmaceutical Research. 25 (4), 805-811 (2008).</li></ol>

作者声明他们没有利益冲突。

由于小鼠是专性鼻呼吸器，通过被动吸入进行初步概念验证研究使效率和剂量估计具有挑战性，因为粉末必须以取决于颗粒特性和粉末分散效率的方式通过鼻子和喉咙7,8,14。本文开发的给药器的使用绕过鼻子和喉咙，将给药器插入第一支气管分叉处9，并将全剂量直接输送到小鼠的肺部，从而为初步研?...

在过去三十年中，由于全球逐步淘汰氯氟烃推进剂1,2，使用干粉吸入器（DPI）进行肺部给药引起了人们的极大兴趣。与其他肺输送系统（如定量吸入器和雾化器）相比，DPI 具有许多优势，包括配方稳定性、便携性、易用性和无推进剂分散机制2。然而，在将DPI产品推向临床转化之前，必须进行几项临床前研究，其中许多研究最初是使用小鼠模型完成的。然而，用于准确和可重复地向小动物输送干粉的技术是有限的。
将干粉输送给小动物（如小鼠）的常用方法包括被动吸入3,4,5,6,7和直接给药8,9,10,11,12,13。被动吸入通常需要一个定制的腔室，该腔室利用大剂量的喷雾干燥粉末来制备足够的气溶胶云。由于小鼠是专性鼻呼吸器14，通过被动吸入输送需要粉末通过鼻子和喉咙到达肺部，因此需要维持具有足够颗粒空气动力学特性的气溶胶云7,8。虽然这是一种有用的技术，在生理上比正常呼吸导致的吸入直接给药更具生理相关性14，但它可能不适合粉末质量有限的初始研究。
或者，已经报道了许多用于直接干粉输送的气管内输送装置8、9、10、11、12、13。气管内装置绕过鼻子和喉咙，将粉末直接输送到肺部，并允许对输送的剂量进行更精细的控制14.此外，一些设备，特别是那些使用夯实加载程序9制备的器械，可以制备较少的量，这是初始概念验证研究的重要考虑因素。缺乏普遍可用的气管内给药装置阻碍了其使用潜力，限制了可用性并导致实验室间差异14.在这项研究中，我们提出了一种简单、廉价、一次性的气管内给药器，可用于开发干粉气溶胶的概念验证小鼠研究。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.6 mL microcentrifuge tubes</td>
			<td>Fisher Scientific</td>
			<td>05-408-120</td>
			<td></td>
		</tr>
		<tr>
			<td>Analytical balance</td>
			<td>Mettler Toledo</td>
			<td>AR1140</td>
			<td>Any analytical balance with sufficient range can be used</td>
		</tr>
		<tr>
			<td>Blunt stainless-steel needle, 1 inch, 21 G</td>
			<td>McMaster-Carr</td>
			<td>75165A681</td>
			<td></td>
		</tr>
		<tr>
			<td>Blunt stainless-steel needle, 1 inch, 22 G</td>
			<td>McMaster-Carr</td>
			<td>75165A683</td>
			<td></td>
		</tr>
		<tr>
			<td>Blunt stainless-steel needle, 1 inch, 25 G</td>
			<td>McMaster-Carr</td>
			<td>75165A687</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable syringe with luer lock (1 mL)</td>
			<td>Fisher Scientific</td>
			<td>14-823-30</td>
			<td>3-mL syringes can also be used</td>
		</tr>
		<tr>
			<td>Female BALB/c mice&#160;</td>
			<td>Charles River, Wilmington, MA, USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>High-performance cascade impactor&#160;</td>
			<td>Next Generation Impactor</td>
			<td>Apparatus 5</td>
			<td></td>
		</tr>
		<tr>
			<td>Lab film (e.g., Parafilm)</td>
			<td>Fisher Scientific</td>
			<td>S37440</td>
			<td></td>
		</tr>
		<tr>
			<td>Low-lint wiper (e.g., Kimwipes)</td>
			<td>Kimberly-Clark Professional</td>
			<td>34133</td>
			<td></td>
		</tr>
		<tr>
			<td>Low-resistance dry powder inhaler&#160;</td>
			<td>RS01 mod 7</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene needle, 1.5 inch, 16 G</td>
			<td>McMaster-Carr</td>
			<td>6934A111</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene needle, 1.5 inch, 18 G</td>
			<td>McMaster-Carr</td>
			<td>6934A53</td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene needle, 1.5 inch, 20 G</td>
			<td>McMaster-Carr</td>
			<td>6934A55</td>
			<td></td>
		</tr>
		<tr>
			<td>Precision sectioning saw</td>
			<td>TedPella</td>
			<td>812-300</td>
			<td>Belt sander can be used as an alternative</td>
		</tr>
		<tr>
			<td>PTFE needle, 2 inch, 20 G</td>
			<td>McMaster-Carr</td>
			<td>75175A694</td>
			<td></td>
		</tr>
		<tr>
			<td>USP General Chapter &#60;601&#62;&#160;</td>
			<td></td>
			<td></td>
			<td>http://www.uspbpep.com/usp31/v31261/usp31nf26s1_c601.asp</td>
		</tr>
	</tbody>
</table>

disposable dosators intended for dry powder delivery to mice

干粉吸入器在将药物输送到肺部方面具有许多优势，包括稳定的固态药物制剂、设备便携性、推注计量和剂量以及无推进剂的扩散机制。为了开发药用干粉气雾剂产品，稳健 的体内 测试至关重要。通常，初步研究涉及在对大型动物物种进行正式研究之前使用小鼠模型进行初步评估。然而，这种方法的一个重大局限性是缺乏合适的设备技术来准确和可重复地将干粉输送给小动物，从而阻碍了此类模型的实用性。为了应对这些挑战，一次性注射器给药器专门用于肺内给药，剂量适合小鼠。这些加料器装载并输送从均匀堆积密度粉末床中获得的预定量的粉末。这种离散控制是通过将钝针插入固定深度（夯实）到粉末床中来实现的，每次去除固定数量。值得注意的是，这种计量模式已被证明对一系列喷雾干燥粉末有效。在涉及四种不同型号喷雾干燥粉末的实验中，加药器证明了能够达到 30 至 1100 μg 范围内的剂量。达到的剂量受夯实剂数量、给药针头尺寸和所用特定配方等因素的影响。这些给药器的主要优点之一是易于制造，使其易于获得且具有成本效益，可在初始概念验证研究期间将干粉输送给小鼠。加料器的一次性特性便于在动物手术室中使用，在这些手术室中，清洁和重新填充可重复使用的系统和称重材料不方便。因此，开发一次性注射器给药器解决了小鼠干粉递送概念验证研究的重大障碍，使研究人员能够在用于肺部药物递送的小动物模型中进行更准确和可重复的初步研究。

The use of dry powder inhalers (DPIs) for pulmonary drug delivery has garnered significant interest over the past three decades due to the global phase-out of chlorofluorocarbon propellants1,2. DPIs offer numerous benefits over other pulmonary delivery systems, such as metered dose inhalers and nebulizers, including formulation stability, portability, ease of use, and propellant-free dispersal mechanisms2. However, before moving DPI products toward clinical translation, several preclinical studies must be conducted, many of which are initially completed using a murine model. Nevertheless, technologies available to deliver dry powders accurately and reproducibly to small animals are limited.
Common methods to deliver dry powders to small animals, such as mice, include passive inhalation3,4,5,6,7 and direct administration8,9,10,11,12,13. Passive inhalation typically requires a custom chamber that utilizes large doses of spray-dried powder to prepare a sufficient aerosol cloud. As mice are obligate nose breathers14, delivery by passive inhalation requires the powder to travel through the nose and throat to reach the lungs, necessitating the maintenance of an aerosol cloud with sufficient particle aerodynamic properties7,8. While a useful technique that is more physiologically relevant than direct delivery due to inhalation as a result of normal breathing14, it may not be suitable for initial studies where powder mass is limited.
Alternatively, a number of intratracheal delivery devices for direct dry powder delivery have been reported8,9,10,11,12,13. Intratracheal devices bypass the nose and throat, delivering the powder directly to the lungs and allowing for finer control over the delivered dose14. Additionally, some devices, especially those prepared using a tamping loading procedure9, can be prepared with smaller quantities, which is an important consideration for initial proof-of-concept studies. The lack of universally available intratracheal delivery devices has hindered their potential for use, limiting availability and leading to interlaboratory differences14. In this study, we propose a simple, inexpensive, disposable dosator for intratracheal delivery that can be utilized for proof-of-concept murine studies in the development of dry powder aerosols.

Author Spotlight: Developing a Disposable Dosator for Preclinical Testing of Dry Powder Inhalers in Small Animal Models 

用于将干粉输送给小鼠的一次性给药器

在用于本研究之前，已确定各种喷雾干燥粉末的气溶胶性能。空气动力学粒度分布 （APSD） 由质量中值空气动力学直径 （MMAD） 和几何标准差 （GSD） 描述，前者表示在第 50个百分位数 （d50） 处将分布一分为二的尺寸，后者反映了分布的广度。GSD 由第 80 个百分位数处的空气动力学直径的平方根除以第 16个百分位数 （d84/d16）1/2 处的平方?...

Watch this Scientific Journal Video about Developing a Disposable Dosator for Preclinical Testing of Dry Powder Inhalers in Small Animal Models at JoVE.com

药物干粉开发需要可靠的 体内 测试，通常使用小鼠模型。用于准确和可重复地将干粉气溶胶输送给小鼠的设备技术受到限制。本研究介绍了用于小鼠相关剂量的肺部药物递送的一次性给药器，有助于初步的概念验证研究。

Dry powder inhalers offer numerous advantages for delivering drugs to the lungs, including stable solid-state drug formulations, device portability, bolus ...

我们正在开发用于分枝杆菌疾病吸入治疗的新药和现有药物。我们的重点是治疗耐药微生物的新方法，确保使用干粉的安全性和有效性。干粉吸入器产品的初步临床前测试通常在小鼠模型中进行，然后再转移到更大的动物模型中。这种方法的一个重大局限性是缺乏合适的设备技术，无法准确和可重复地将干粉输送给小动物。我们开发的一次性给药器易于制造，使其易于获得且具有成本效益，可用于小鼠的初步概念验证研究。一次性特性允许它们在动物手术室中使用，而无需担心清洁、重新填充和称量可重复使用设备的材料。我们未来的工作将采用针对病原体的生物治疗部分，以避免对宿主产生任何影响。然后，这种方法可以针对患者进行定制，因为它具有病原体特异性。

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Research

Education

JoVE Core

JoVE Journal

Pharmacokinetics and Pharmacodynamics

Medicine

Unit 1

Disposable Dosators Intended for Dry Powder Delivery to Mice

Pharmacokinetics and Pharmacodynamics: Introduction

SCIENTISTS IN ACTION

644 次观看.  RTI International. 我们正在开发用于分枝杆菌疾病吸入治疗的新药和现有药物。我们的重点是治疗耐药微生物的新方法，确保使用干粉的安全性和有效性。干粉吸入器产品的初步临床前测试通常在小鼠模型中进行，然后再转移到更大的动物模型中。这种方法的一个重大局限性是缺乏合适的设备技术，无法准确和可重复地将干粉输送给小动物。我们开发的一次性给药器易于制造，使其易于?...

视频: Author Spotlight: Developing a Disposable Dosator for Preclinical Testing of Dry Powder Inhalers in Small Animal Models 

Dry powder inhalers offer numerous advantages for delivering drugs to the lungs, including stable solid-state drug formulations, device portability, bolus metering and dosing, and a propellant-free dispersal mechanism. To develop pharmaceutical dry powder aerosol products, robust in vivo testing is essential. Typically, initial studies involve using a murine model for preliminary evaluation before conducting formal studies in larger animal species. However, a significant limitation in this approach is the lack of suitable device technology to accurately and reproducibly deliver dry powders to small animals, hindering such models&#39; utility. To address these challenges, disposable syringe dosators were developed specifically for intrapulmonary delivery of dry powders in doses appropriate for mice. These dosators load and deliver a predetermined amount of powder obtained from a uniform bulk density powder bed. This discrete control is achieved by inserting a blunt needle to a fixed depth (tamping) into the powder bed, removing a fixed quantity each time. Notably, this dosing pattern has proven effective for a range of spray-dried powders. In experiments involving four different model spray-dried powders, the dosators demonstrated the ability to achieve doses within the range of 30 to 1100 &#181;g. The achieved dose was influenced by factors such as the number of tamps, the size of the dosator needle, and the specific formulation used. One of the key benefits of these dosators is their ease of manufacturing, making them accessible and cost-effective for delivering dry powders to mice during initial proof-of-concept studies. The disposable nature of the dosators facilitates use in animal procedure rooms, where cleaning and refilling reusable systems and weighing materials is inconvenient. Thus, developing disposable syringe dosators has addressed a significant hurdle in murine dry powder delivery for proof-of-concept studies, enabling researchers to conduct more accurate and reproducible preliminary studies in small animal models for pulmonary drug delivery.

Pharmaceutical dry powder development necessitates reliable in vivo testing, often using a murine model. Device technology for accurately and reproducibly delivering dry powder aerosols to mice is restricted. This study presents disposable dosators for pulmonary drug delivery at mouse-relevant doses, aiding initial proof-of-concept research.

科研

医学

Assembling and Actuating a Disposable Dosator for Dry Powder Drug Delivery

To prepare the disposable dosator and its filling components, take a 2.5 centimeter or 1 inch blunt stainless steel needle of 21 to 25 gauge. Utilizing a precision sectioning saw or a belt sander, trim the plastic lure part of the needle, leaving about 2 to 3 millimeters of the plastic lure attached to the needle. Next, cut off approximately 1 to 1.5 centimeters from the tip of a 0.6 milliliter conical centrifuge tube.After that, fill this cut tip with 30 to 35 milligrams of the powder of interest. For storing or transporting the powder, place the cutoff tube cap onto the cut tip containing the powder. Use paraffin film to wrap the cover, minimizing the powder's exposure to ambient moisture.To load the dosator, tamp the trimmed stainless steel needle into the powder bed in the cut tip as many times as required to achieve the desired dose. Using a low lint wiper, gently wipe the sides of the needle to remove any excess powder. Then take a 3.81 centimeter or 1.5 inch polypropylene needle of 16 to 20 gauge and cautiously insert the loaded stainless steel needle into it, making sure not to dislodge any powder.Alternatively, use a 5.08 centimeter or 2 inch PTFE needle for the same. To actuate the dosator, first draw back a disposable syringe to the desired volume based on the application. Then attach the syringe to the lure lock on the polypropylene or PTFE needle before inserting the needle end of the dosator into the desired target.To analyze powder content and reproducibility, insert the dosator needle through a perforated rubber septum or paraffin film into a vial with a small quantity of liquid. Forcefully depress the syringe plunger, expelling the powder from the device into the collection vial. Finally, analyze the powder solution in the vial using UV's visible spectra photometry to monitor the dose of the powder released from the dosator.Four different spray dried powders visualized using scanning electron microscopy were considered for delivery using the demonstrated dosator. The delivered dose as a function of the number of Tamps in the powder bed, was obtained from UV visible spectra photometry of the powder solutions. Notably, all spray dried powders demonstrated a linear dose response from 1 to 4 Tamps.The first Tamp always incurred a larger dose of powder than subsequent Tamps. When compared to the demonstrated 21 gauge stainless steel with a 16 gauge polypropylene dosator, a slight increase in achievable dose was observed using a 21 gauge stainless steel with a 20 gauge PTFE dosator for powder SD 1. As expected, the achievable dose of SD 1 decreased for a 22 gauge stainless steel with an 18 gauge polypropylene dosator, having a smaller inner needle diameter.A 25 gauge stainless steel with a 20 gauge polypropylene dosator further decreased the initial and subsequent Tamp doses. This is a comparison of the four dosator systems that were evaluated, highlighting that the dosators can be customized to meet different dosage needs.