Name: disposable dosators for pulmonary insufflation of therapeutic agents to small animals
Uploaded: 2017-03-30T13:00:00
Description: Watch this Scientific Journal Video about Disposable Dosators for Pulmonary Insufflation of Therapeutic Agents to Small Animals at JoVE.com

Authors would like to kindly thank the National Institute for Allergy and Infectious Disease for the funding to conduct this research.

1. Preparation of Components of the Dosators
<ol>
	<li>Perforate the bottom of a 0.5 mL polypropylene microcentrifuge tube by drilling or by simply grinding or cutting off the bottom with a grinding wheel or a sharp pair of scissors. Ensure that the hole is in the center and is no more than 2 mm in diameter and no less than 1 mm in diameter (Figure 1).</li>
	<li>Perforate the top of the microcentrifuge tube. Using a #22 drill bit (approximately 4 mm in diameter), drill a hole in the center of the cap. ...

<ol>
	<li>Young, E. F., 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=Inhaled+Pyrazinoic+Acid+Esters+for+the+Treatment+of+Tuberculosis.">Inhaled Pyrazinoic Acid Esters for the Treatment of Tuberculosis.</a> Pharmaceutical Research. , 1-11 (2016).</li><li>Hinds, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles. , (2012).</li><li>Islam, N., Gladki, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dry+powder+inhalers+(DPIs)-A+review+of+device+reliability+and+innovation.">Dry powder inhalers (DPIs)-A review of device reliability and innovation.</a> International Journal of Pharmaceutics. 360 (1-2), 1-11 (2008).</li><li>Chan, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dry+powder+aerosol+delivery+systems:+current+and+future+research+directions.">Dry powder aerosol delivery systems: current and future research directions.</a> J Aerosol Med. 19 (1), 21-27 (2006).</li><li>Vehring, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharmaceutical+Particle+Engineering+via+Spray+Drying.">Pharmaceutical Particle Engineering via Spray Drying.</a> Pharmaceutical Research. 25 (5), 999-1022 (2008).</li><li>Bosquillon, C., Lombry, C., Pr&#233;at, V., Vanbever, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+formulation+excipients+and+physical+characteristics+of+inhalation+dry+powders+on+their+aerosolization+performance.">Influence of formulation excipients and physical characteristics of inhalation dry powders on their aerosolization performance.</a> Journal of Controlled Release. 70 (3), 329-339 (2001).</li><li>Hickey, A. J., Concessio, N. M., Van Oort, M. M., Platz, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+influencing+the+dispersion+of+dry+powders+as+aerosols.">Factors influencing the dispersion of dry powders as aerosols.</a> Pharmaceutical Technology. 18 (8), 58-64 (1994).</li><li>Garcia-Contreras, L., 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=Inhaled+large+porous+particles+of+capreomycin+for+treatment+of+tuberculosis+in+a+guinea+pig+model.">Inhaled large porous particles of capreomycin for treatment of tuberculosis in a guinea pig model.</a> Antimicrob Agents Chemother. 51 (8), 2830-2836 (2007).</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=Spray+Dried+Aerosol+Particles+of+Pyrazinoic+Acid+Salts+for+Tuberculosis+Therapy.">Spray Dried Aerosol Particles of Pyrazinoic Acid Salts for Tuberculosis Therapy.</a> Molecular Pharmaceutics. 12 (8), 2574-2581 (2015).</li><li>Sung, J. 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=Dry+powder+nitroimidazopyran+antibiotic+PA-824+aerosol+for+inhalation.">Dry powder nitroimidazopyran antibiotic PA-824 aerosol for inhalation.</a> Antimicrob Agents Chemother. 53 (4), 1338-1343 (2009).</li><li>Guillon, A., 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=Pulmonary+delivery+of+dry+powders+to+rats:+tolerability+limits+of+an+intra-tracheal+administration+model.">Pulmonary delivery of dry powders to rats: tolerability limits of an intra-tracheal administration model.</a> Int J Pharm. 434 (1-2), 481-487 (2012).</li><li>Morello, 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=Dry-powder+pulmonary+insufflation+in+the+mouse+for+application+to+vaccine+or+drug+studies.">Dry-powder pulmonary insufflation in the mouse for application to vaccine or drug studies.</a> Tuberculosis. 89 (5), 371-377 (2009).</li></ol>

The dispersion from the dosators was suitable for animals to receive a therapeutic dose via passive nose-only respiration, indicating a large proportion of aerosol dispersed to primary particle size. These dosators can be used for endotracheal administration, in vitro evaluation of powder performance, and general purpose dry powder aerosol dispersion for analytical or efficacious experiments. If used for intrapulmonary delivery, it is important to use an appropriate volume of air for the species chosen, as over-...

Development of new therapeutic products requires efficacy testing in an animal model. The pulmonary route of administration can be utilized to deliver drugs locally and systemically 1. Evaluation of dry powder aerosols necessitates an efficient dispersion mechanism to maintain high concentrations in an exposure chamber or for direct endotracheal administration. While solutions exist to expose animals by passive inhalation to dry powder aerosols, most require masses of powder in large excess of the dose delivered 2.
This precludes conducting early feasibility studies as insufficient drug is available at the research or early development stage to support the dose delivery requirements for conventional aerosol delivery systems.
When designing an aerosol drug product, aerodynamic performance can relate directly to delivery efficiency and efficacy 3. Dispersion of powder into an aerosol requires energy input sufficient to overcome interparticulate forces, and particle engineering approaches can substantially improve aerosol performance 4,5,6. We have developed a dispersion system (dosator) which can aerosolize engineered dry powder aerosols efficiently for the purpose of direct pulmonary insufflation, dispersion into an exposure system or generation for analytical purposes.

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	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:695px;">0.5 mL microcentrifuge tube</td>
			<td style="width:139px;">VWR</td>
			<td style="width:119px;">89000-026</td>
			<td style="width:207px;"></td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">High-Volume Particle-Filtering Stainless Steel Wire Cloth, Woven, 304 Stainless Steel, 60 x 60 Mesh, .0045&#34; Wire Diameter</td>
			<td style="width:139px;">McMaster Carr</td>
			<td style="width:119px;">9230T44</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Stainless Steel Dispensing Needle, Straight, 18 Gauge, 1&#34; Long</td>
			<td style="width:139px;">McMaster Carr</td>
			<td style="width:119px;">75165A676</td>
			<td>Any luer-fit needle will suffice</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:695px;">Cotton balls</td>
			<td style="width:139px;">McMaster Carr</td>
			<td style="width:119px;">54845T16</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:695px;">Parafilm M&#174; Laboratory Film</td>
			<td style="width:139px;">VWR</td>
			<td>100229-550</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Black-Oxide High-Speed Steel Jobbers&#39; Drill Bit, Wire Gauge 22, 3-1/8&#34; Overall Length, 1.8&#34; Drill Depth, 135Deg Point</td>
			<td style="width:139px;">McMaster Carr</td>
			<td style="width:119px;">2901A195</td>
			<td></td>
		</tr>
	</tbody>
</table>

disposable dosators for pulmonary insufflation of therapeutic agents to small animals

Development of new therapeutic products requires efficacy testing in an animal model. The pulmonary route of administration can be utilized to deliver drugs locally and systemically. Evaluation of dry powder aerosols necessitates an efficient dispersion mechanism to maintain high concentrations in an exposure chamber or for direct endotracheal administration. While solutions exist to expose animals by passive inhalation to dry powder aerosols, most require masses of powder in large excess of the dose delivered. This precludes conducting early feasibility studies as insufficient drug is available at the research or early development stage to support the dose delivery requirements for conventional aerosol delivery systems. When designing an aerosol drug product, aerodynamic performance can relate directly to delivery efficiency and efficacy. Dispersion of powder into an aerosol requires energy input sufficient to overcome interparticulate forces, and particle engineering approaches can substantially improve aerosol performance. We have developed a dispersion system (dosator) which can aerosolize engineered dry powder aerosols efficiently for the purpose of direct pulmonary insufflation, dispersion into an exposure system or generation for analytical purposes.

For easily dispersible powders such as those spray-dried with the intent for pulmonary delivery 5,8,9, the dosators deliver a bolus dose out of the device. There are many applications for the dosators, including in vitro particle characterization, direct intrapulmonary administration in live animals, and aerosol generation for passive inhalation systems.
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Watch this Scientific Journal Video about Disposable Dosators for Pulmonary Insufflation of Therapeutic Agents to Small Animals at JoVE.com

Disposable Dosators for Pulmonary Insufflation of Therapeutic Agents to Small Animals

During development of drugs for pulmonary delivery, it is necessary to evaluate pharmacokinetics and efficacy in an animal model. We present a method to build a disposable aerosol dispersion system from of-the-shelf components that can be used to administer intrapulmonary dry powder aerosol to rodents.

Development of new therapeutic products requires efficacy testing in an animal model. The pulmonary route of administration can be utilized to deliver ...

The overall goal of this procedure is to assemble a disposable aerosol dispersion system for use in dry powder aerosol development and evaluation. This technique addresses key questions in pharmaceutics and aerosol science with respect to the delivery of dry powder aerosols of importance to pharmacokinetics and also efficacy testing, and it currently meets an unmet need. The main advantage of this technique is that it uses Dosators that are made from readily available materials and those materials are fairly economic.One serious advantage is that they can be used in a hazardous environment because the materials themselves are disposable. Begin by perforating the bottom of a 0.5 milliliter polypropylene microcentrifuge tube with a one to two milliliter diameter hole. Next, use a number 22 drill bit to create an approximately four millimeter diameter hole in the center of the microcentrifuge cap.Punch out a 60 by 60 millimeter mesh with a 0.0045 inch wire diameter screen and a five millimeter outer diameter from a 304 stainless steel wire cloth and use the end of a blunt tip needle to insert the screen into the bottom of the microcentrifuge tube so that it covers the perforation. Then, press fit the narrow end of the microcentrifuge tube tip into the end of the needle with enough pressure to adhere the tube tip to the needle without cracking the plastic, and use ethanol to gently clean the top of the needle and the bottom of the tube. Assembling the Dosator while it is still wet, assist in achieving a tight fit Although the materials can also be wrapped with lab film after mating to provide additional stability as necessary.After tearing an analytical microbalance, load the powder into the Dosator and use a forceps to plug the top of the microcentrifuge tube with cotton. Next, close the microcentrifuge tube cap and draw back a syringe plunger to the appropriate volume according to the specific experimental application. Then, insert the syringe into the back end of the Dosator with the needle end of the Dosator in the dosing port of the exposure chamber, and depress the plunger forcefully to expel the powder out of the device into the chamber.The dosing chamber can be assembled from acrylic with a three inch long, four inch diameter central aerosol compartment, and tapered nose cones for evaluation of the aerosol exposure by passive inhalation. In this representative experiment, a spray dried drug powder of a mass median aerodynamic diameter of 2.9 micrometers was administered to guinea pigs in a dosing chamber using the delivery technique as demonstrated. Five 10 milligram doses of powder given at three minute intervals resulted in a maximum plasma concentration of five micrograms per milliliter, a similar concentration to that observed for endotracheal administration of one milligram per kilogram of powder by standard methods, indicating that the dosing chamber powder delivery is an efficient means of dispersion to the primary particle size.Once used to the method, the Dosator assembly and filling can be accomplished in approximately five minutes if performed properly. After its development, this technique allowed researchers in the field of pulmonary drug delivery to explore novel tuberculosis therapies in a guinea pig model of disease. After watching this video, you should have a good understanding of how to build disposable Dosators for the dispersion of engineered dry powder aerosols.Don't forget that working with some types of machinery can be hazardous, and precautions such as wearing safety glasses should always be taken when working with these materials.

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