Name: evaluation of drug sorption to pvc- and non-pvc-based tubes in administration sets using a pump
Uploaded: 2017-03-11T14:00:00
Description: Watch this Scientific Journal Video about Evaluation of Drug Sorption to PVC- and Non-PVC-based Tubes in Administration Sets Using a Pump at JoVE.com

This work was supported by the Korea Ministry of Environment (MOE) as part of the "The advancement of scientific research and technological development in environmental science program (E315-00015-0414-2)."

1. Preparation of Tubes in Administration Sets
NOTE: Precisely perform the cutting step to eliminate the effect of differences in tube length on drug sorption.
<ol>
	<li>Label the end of the tubes with the tube type (e.g., PVC, polyurethane (PU), and polyolefin (PO)) using a marker.</li>
	<li>Remove all detachable accessories, such as connectors and needle covers.</li>
	<li>Using a sharp razor to ensure clean edges, cut the tubes to 1 m in length from the connection of the drip cham...

<ol>
	<li>Jin, S. E., You, S., Jeon, S., Hwang, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diazepam+sorption+to+PVC-+and+non-PVC-based+tubes+in+administration+sets+with+quantitative+determination+using+a+high-performance+liquid+chromatographic+method.">Diazepam sorption to PVC- and non-PVC-based tubes in administration sets with quantitative determination using a high-performance liquid chromatographic method.</a> Int. J. Pharm. 506, 414-419 (2016).</li><li>Treleano, A., Wolz, G., Brandsch, R., Welle, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+into+the+sorption+of+nitroglycerin+and+diazepam+into+PVC+tubes+and+alternative+tube+materials+during+application.">Investigation into the sorption of nitroglycerin and diazepam into PVC tubes and alternative tube materials during application.</a> Int. J. Pharm. 369, 30-37 (2009).</li><li>Shibata, N., 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=Adsorption+and+pharmacokinetics+of+cyclosporin+A+in+relation+to+mode+of+infusion+in+bone+marrow+transplant+patients.">Adsorption and pharmacokinetics of cyclosporin A in relation to mode of infusion in bone marrow transplant patients.</a> Bone Marrow Transplant. 25, 633-638 (2000).</li><li>Kawano, K., Tsubouchi, R., Nakajima, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Effect+of+the+Drip+Condition+(Container+Materials,+Concentration,+Drip+Rate)+on+the+Sorption+of+Nicardipine+Hydrochloride+from+Injection+to+the+Intravenous+Infusion+Set.">The Effect of the Drip Condition (Container Materials, Concentration, Drip Rate) on the Sorption of Nicardipine Hydrochloride from Injection to the Intravenous Infusion Set.</a> Jap. J. Hosp. Pharm. 18, 491-495 (1992).</li><li>Hanawa, T., 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=Investigation+of+the+release+behavior+of+diethylhexyl+phthalate+from+the+polyvinyl-chloride+tubing+for+intravenous+administration.">Investigation of the release behavior of diethylhexyl phthalate from the polyvinyl-chloride tubing for intravenous administration.</a> Int. J. Pharm. 210, 109-115 (2000).</li><li>Mason, N. A., Cline, S., Hyneck, M. L., Berardi, R. R., Ho, N. F., Flynn, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+affecting+diazepam+infusion:+solubility,+administration-set+composition,+and+flow+rate.">Factors affecting diazepam infusion: solubility, administration-set composition, and flow rate.</a> Am. J. Hosp. Pharm. 38, 1449-1454 (1981).</li><li>Roberts, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+solute+sorption+into+plastic+tubing+during+organ+perfusion+and+intravenous+infusions.">Modeling solute sorption into plastic tubing during organ perfusion and intravenous infusions.</a> J. Pharm. Sci. 85, 655-665 (1996).</li><li>Patel, P., Panchal, S., Mehta, T., Solanki, S., Patel, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversed-Phase+High+Performance+Liquid+Chromatographic+(RP-HPLC)+Method+For+Determination+of+tacrolimus+in+bulk+and+pharmaceutical+formulation.">Reversed-Phase High Performance Liquid Chromatographic (RP-HPLC) Method For Determination of tacrolimus in bulk and pharmaceutical formulation.</a> Int. J. Pharm. Pharm. Sci. 3, 220-222 (2011).</li><li>Mercolini, L., Mandrioli, R., Iannello, C., Matrisciano, F., Nicoletti, F., Raggi, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+analysis+of+diazepam+and+its+metabolites+in+rat+plasma+and+brain+tissue+by+HPLC-UV+and+SPE.">Simultaneous analysis of diazepam and its metabolites in rat plasma and brain tissue by HPLC-UV and SPE.</a> Talanta. 80, 279-285 (2009).</li><li>Wang, X., 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=Deposition+of+diazepam+and+its+metabolites+in+hair+following+a+single+dose+of+diazepam.">Deposition of diazepam and its metabolites in hair following a single dose of diazepam.</a> Int. J. Legal. Med. , (2016).</li><li>Wallemacq, P., 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=Multi-site+Analytical+Evaluation+of+the+Abbott+ARCHITECT+Tacrolimus+Assay.">Multi-site Analytical Evaluation of the Abbott ARCHITECT Tacrolimus Assay.</a> Ther. Drug. Monit. 31 (2), 198-204 (2009).</li><li>Morar-Mitrica, S., 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+of+a+stable+low-dose+aglycosylated+antibody+formulation+to+minimize+protein+loss+during+intravenous+administration.">Development of a stable low-dose aglycosylated antibody formulation to minimize protein loss during intravenous administration.</a> MAbs. 7 (4), 792-803 (2015).</li><li>Trissel, L. A., Xu, Q. A., Baker, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug+compatibility+with+new+polyolefin+infusion+solution+containers.">Drug compatibility with new polyolefin infusion solution containers.</a> Am. J. Health Syst. Pharm. 63, 2379-2382 (2006).</li><li>Cloyd, J. C., Vezeau, C., Miller, 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=Availability+of+diazepam+from+plastic+containers.">Availability of diazepam from plastic containers.</a> Am. J. Hosp. Pharm. 37, 492-496 (1980).</li><li>Ceccherini, G., Perondi, F., Lippi, I., Grazia, G., Marchetti, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravenous+lipid+emulsion+and+dexmedetomidine+for+treatment+of+feline+permethrin+intoxication:+a+report+from+4+cases.">Intravenous lipid emulsion and dexmedetomidine for treatment of feline permethrin intoxication: a report from 4 cases.</a> Open Veterinary Journal. 5 (2), 113-121 (2015).</li><li>Lei, W., Yu, C., Lin, H., Zhou, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+tacrolimus-loaded+transfersomes+for+deeper+skin+penetration+enhancement+and+therapeutic+effect+improvement+in+vivo.">Development of tacrolimus-loaded transfersomes for deeper skin penetration enhancement and therapeutic effect improvement in vivo.</a> Asian J. Pharm. Sci. 8, 336-345 (2013).</li><li>Maiguy-Foinard, A., Blanchemain, N., Barthelemy, C., Decaudin, B., Odou, P. <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+a+double-lumen+extension+tube+on+drug+delivery:+examples+of+isosorbide+dinitrate+and+diazepam.">Influence of a double-lumen extension tube on drug delivery: examples of isosorbide dinitrate and diazepam.</a> PLoS One. 11 (5), 0154917 (2016).</li></ol>

Drug sorption to administration sets is a cause of unexpected drug loss in intravenous drug delivery. During sorption, drugs are generally partitioned to polymeric materials of tubes at the early phase of infusion; after sorption equilibrium is reached, the delivered amount of drug is stabilized1. The sorption levels of drugs should be evaluated and minimized. Several evaluation methods for drug sorption have been studied, such as a pump method and a drip method. Compared to the drip method, the p...

Administration sets are composed of a spike, a drip chamber, tubes, Luer adapters (connectors), and a needle cover for protection. Other accessories, such as an airway check valve, a regulating clamp, an in-line filter, a Y-tube with cap (an injection port), and a needle, can also be attached to administration sets. Drug sorption to tubes is a critical issue in the delivery of injectable drugs1. Sorption describes the adsorption of a drug to the polymer surface and the absorption of a drug into the polymeric matrix2. Drug sorption to tubes in administration sets causes unpredictable drug loss and makes it difficult to control the delivered drug concentration. Drug sorption to polymeric tubes is therefore a major impediment to the precise transfer of injectable drugs into the body. However, there are no standard methods or regulatory guidelines for the evaluation of drug sorption to tubes in administration sets.
The levels of drug sorption to tubes in administration sets have been reported using various evaluation methods1,2,3,4,5. Test methods and model drugs are key factors in sorption evaluation. The pump method1,3 and drip method4,5 have been widely used for sorption tests. In general, the pump method should be used in the case of drugs with low concentrations and low flow rates as the infusion conditions. Using various evaluation methods, many studies of drug sorption have been reported for polyvinyl chloride (PVC)- and non-PVC-based tubes in administration sets1,2,3,5. Many sorptive drugs can be selected to investigate whether the tubes of the administration sets have drug sorption potential or not. Diazepam (Figure 1a)1, 2, tacrolimus (Figure 1b)5, nitroglycerin2, and cyclosporin A3 are representative drugs with high sorption in PVC- and non-PVC-based tubes.
For the evaluation of drug sorption to the tubes, test conditions such as flow rate and drug concentration are based on the clinical use of the selected drugs1, 6, 7. In the case of diazepam, a high concentration of 100 &#181;g/mL was used at a flow rate of 1 mL/min to mimic the initial dose for the treatment of status epilepticus1. For tacrolimus, a concentration of 10 &#181;g/mL was delivered at a flow rate of 10 mL/h. Dextrose solution (5%) was used for the dilution of drug injections, and tube length was fixed at 1 m. Glass bottles and vials should be used to prevent additional sorption during the experiment and storage.
In this study, we conducted a kinetic sorption study with the model drugs, diazepam and tacrolimus, using a pump method. Specific details of this protocol, from tube preparation to sorption evaluation, were described previously. Methods for the evaluation of drug sorption have already been used to confirm drug properties for injections and to recommend the clinical use of injections with administration sets on a case-by-case basis1,2,3,4,5,6,7. This protocol may be used as a standard technique for the sorption evaluation of administration sets. International standards for the evaluation of drug sorption to tubes may be necessary to ensure the safety and efficacy of drug delivery.

<table>
	<tbody>
		<tr>
			<td>PVC IV sets</td>
			<td>Becton Dickinson 
			(BD) Co. Ltd. (Franklin Lakes, NJ, USA)</td>
			<td></td>
			<td>Internal diameter: 2.54 mm</td>
		</tr>
		<tr>
			<td>PU IV sets</td>
			<td>Tianjin Hanaco Medical (THM) Co.Ltd. 
			(Tianjin, China)</td>
			<td></td>
			<td>Non-PVC 
			Internal diameter: 2.54 mm</td>
		</tr>
		<tr>
			<td>Non-PVC Polyolefin IV sets</td>
			<td>Polyscientech, Co. Ltd (Anseong, Korea)</td>
			<td></td>
			<td>Non-PVC [PE elastomer/PP elastomer/PB elastomer(25/50/25, weight ratio) blend] 
			Internal diameter: 2.54 mm</td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Korea Vaccine Co. Ltd. (Seoul, Korea)</td>
			<td>KOVAX-SYRINGE 1 mL 26G 1/2&#34;</td>
			<td></td>
		</tr>
		<tr>
			<td>Daewon diazepam injection</td>
			<td>Daewon Pharma. Co. Ltd. (Hwaseong, Gyunggi, Korea)</td>
			<td></td>
			<td>1 mg/mL, total 2 mL 
			Batch No.: P003 
			Composition: diazepam, propylene glycol, ethanol, benzyl alcohol, sodium benzoate, bezoic acid, water for injection</td>
		</tr>
		<tr>
			<td>Tacrobel injection</td>
			<td>Chong Keun Dang, Co. Ltd. (Seoul, Korea)</td>
			<td></td>
			<td>5 mg/mL, total 1 mL 
			Batch No.: AG002 
			Composition: tacrolimus hydrate, polyoxyl 60 hydrogenated castor oil (HCO-60), dehydrated alcohol</td>
		</tr>
		<tr>
			<td>5% Dextrose</td>
			<td>JW Pharmaceutical (Seoul, Korea)</td>
			<td>500 mL</td>
			<td></td>
		</tr>
		<tr>
			<td>5% Dextrose</td>
			<td>Daehan Pharmaceutical (Seoul, Korea)</td>
			<td>200 mL</td>
			<td>Bottle (glass)</td>
		</tr>
		<tr>
			<td>Amber vials</td>
			<td></td>
			<td>20 mL</td>
			<td>Glass</td>
		</tr>
		<tr>
			<td>Terumo infusion pump</td>
			<td>Terumo (Medical Corp., USA)</td>
			<td>TE-135</td>
			<td></td>
		</tr>
		<tr>
			<td>HPLC system with UV detector</td>
			<td>Agilent (Santa Clara, CA, USA)</td>
			<td>Agilent 1260</td>
			<td></td>
		</tr>
		<tr>
			<td>CAPCELL PAK C18 column&#160;</td>
			<td>Shiseido (Japan)</td>
			<td>90404</td>
			<td>1.5 mm x 250 mm, 5 &#956;m</td>
		</tr>
		<tr>
			<td>Diazepam</td>
			<td></td>
			<td></td>
			<td>From Daewon Pharma. Co., Ltd.</td>
		</tr>
		<tr>
			<td>Tacrolimus</td>
			<td>Teva Czech industries&#160; (Czech Republic)</td>
			<td></td>
			<td>From Chong Keun Dang, Co. Ltd.</td>
		</tr>
		<tr>
			<td>Acetonitrile</td>
			<td>Burdick and Jackson Co., Ltd. (MI, USA)</td>
			<td>3/1/9017</td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Burdick and Jackson Co. Ltd. (MI, USA)</td>
			<td>AH230-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Water</td>
			<td>Burdick and Jackson Co. Ltd. (MI, USA)</td>
			<td>3/1/4218</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium dihydrogen phosphate</td>
			<td>Sigma (St. Louis, MO, USA)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphoric acid</td>
			<td>Sigma (St. Louis, MO, USA)</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

evaluation of drug sorption to pvc- and non-pvc-based tubes in administration sets using a pump

Administration sets are delivery tools for the direct application of drugs into the body and are composed of a spike, a drip chamber, tubes, Luer adapters (connectors), a needle cover for protection, and other accessories. Drug sorption to tubes of administration sets is a critical issue in terms of safety and efficacy. Although drug sorption is an important factor in the quality of an administration set, there are no standard evaluation methods for the regulation of drug sorption to the tubes. Here, we describe an evaluation protocol for drug sorption to tubes of administration sets. Tubes made of polyvinyl chloride (PVC)- and non-PVC-based polymeric materials were cut to 1 m in length. Diazepam and tacrolimus were used as model drugs. In the kinetic sorption study, we selected the drug concentration and flow rate based on the clinical usage of these drugs. After the dilution of each drug in a glass bottle, the diluted drug solution was delivered through tubes of administration sets using a pump. Samples were collected in amber vials at appropriate time points and the drugs were analyzed using high-performance liquid chromatography. Drug concentrations and sorption levels to tubes of the administration sets were calculated. Acceptable criteria to ensure the quality of administration sets are recommended.

The sorption to tubes in the administration set was kinetically monitored using the model drugs, diazepam (Figure 1a) and tacrolimus (Figure 1b), and the pump method (Figure 2). Diluted drug (Figure 2a) was passed through PVC- and non-PVC-based tubes (Figure 2b) at a fixed flow rate using an infusion pump (Figure 2c). The glass bottle was opened slightly to allow the insertion of the admi...

Watch this Scientific Journal Video about Evaluation of Drug Sorption to PVC- and Non-PVC-based Tubes in Administration Sets Using a Pump at JoVE.com

Evaluation of Drug Sorption to PVC- and Non-PVC-based Tubes in Administration Sets Using a Pump

We report a method for drug sorption evaluation using a pump and model drugs (diazepam and tacrolimus). After drug analysis using high-performance liquid chromatography, drug concentrations and sorption levels in the tubes of administration sets are calculated.

Administration sets are delivery tools for the direct application of drugs into the body and are composed of a spike, a drip chamber, tubes, Luer adapters ...

The overall goal of this protocol is to evaluate the drug sorption of tubes in administration sets using an infusion pump. This method can help answer key questions in the quality evaluation field to help develop the tubes in administration sets suitable for injectable drug formulations. Though this method can provide insight into the sorption evaluation of drug to tubes in administration sets.It can also be applied to other systems, like accessorized tubes of administration sets. Demonstrating the procedure will be Dr.Su-Eon Jin, a research professor from my laboratory. To begin this procedure, label the tube type on the end of each tube.Then, remove all detachable accessories, such as connectors and needle coverings. Using a sharp razor, cut the tube to one meter in length from the connection of the drip chamber. Next, in labeled one liter glass bottles, dilute the drug injections with a five percent dextrose solution.Gently swirl the bottles to mix each drug solution. Transfer the diluted solution to an amber vial. It is important to mix the drug solution gently to prevent the generation of bubbles in bottles.First, confirm the tube depending flow rate using a pump, as outlined in the text protocol. Then, connect the end of one tube to a syringe. Immerse the other end in a bottled drug injection.Pull back on the syringe plunger until the tube is completely filled with drug solution. Next, open the door of the infusion pump and push the release lever. Insert the preloaded tube into the infusion pump.Removing the bubbles from tubes in administration sets is a required technique after loading the drug solution. After this, remove the syringe. Place a chemically-resistant borosilicate glass graduated cylinder over the end of the tube to collect the drug solution after it passes through.Set the flow rate, as outlined in the text protocol. Using amber vials, collect sample at room temperature at various time points. To begin, prepare standard drug solutions, as outlined in the text protocol.After this, inject ten microliters of each standard into an HPLC system with UV detection equipped with a C18 column. Confirm the specificity and linearity, and obtain calibration curves, as outlined in the text protocol. Next, dilute the drug samples as needed to fall within the calibration range.Directly inject ten microliters of each diluted sample into the HPLC system. Then, calculate the drug concentration and sorption level, as outlined in the text protocol. In this study, drug absorption to PVC and non-PVC based tubes were evaluated using a pump and model drugs.High performance liquid chromatography is then used to calculate drug concentrations and sorption levels in the tubes. A chromatogram of diazepam shows the drug peak at eight point two minutes, with interfering peaks that did not overlap. Sorption levels are then determined by calculating the percentage of remaining drug content after passage through the tubes.Sorption is seen to be the highest in PVC-based tubes, and lowest in PO based tubes, during the initial phase of the kinetic sorption test. The tacrolimus chromatogram shows a drug peak at six point eight minutes, with no interfering peaks. The determined sorption levels shows a similar trend with sorption being highest in PVC based tubes and lowest for PO based tubes.Once mastered, this technique can be done in one to four hours if it is performed properly. While attempting this procedure, it's important to remember to use glass-based containers, except on tubs of administration sets. After its development, this technique paved the way for researchers in the field of quality evaluation of administration sets, depending on the injectable drug formulations to explore physicochemical phenomena of drug sorption in tubes of administration sets during intravenous infusion.After watching this video, you should have a good understanding of how to perform a sorption kinetic study using a pump, and how to evaluate a drug sorption levels in tubes of administration sets. When the drug loss due to sorption in PVC-based tubes is found, we recommend using non-PVC-based tubes, such as polyolefin-based ones to minimize unwanted sorption.

evaluation-drug-sorption-to-pvc-non-pvc-based-tubes-administration

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Medicine

Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements

In multiple fields of study, access to the circulatory system in laboratory studies is necessary. Pharmacological studies in rats using chronically implanted catheters permit a researcher to effectively and humanely administer substances, perform repeated blood sampling and assists in conscious direct measurements of blood pressure and heart rate. Once the catheter is implanted long-term sampling is possible. Patency and catheter life depends on multiple factors including the lock solution used, flushing regimen and catheter material. This video will demonstrate the methodology of femoral artery and venous catheterization of the rat. In addition the video will demonstrate the use of the femoral venous and arterial catheters for blood sampling, drug administration and use of the arterial catheter in taking measurements of blood pressure and heart rate in a conscious freely-moving rat. A tether and harness attached to a swivel system will allow the animal to be housed and have samples taken by the researcher with minimal disruption to the animal. To maintain patency of the catheter, careful daily maintenance of the catheter is required using lock solution (100 U/ml heparinized saline), machine-ground blunt tip syringe needles and the use of syringe filters to minimize potential contamination. With careful aseptic surgical techniques, proper catheter materials and careful catheter maintenance techniques, it is possible to sustain patent catheters and healthy animals for long periods of time (several weeks).

Chronic catheterization of blood vessels in the rat is often required for administration of substances, obtain blood sample over a period of time or for direct conscious blood pressure measurements. Femoral arterial catheterization of the rat and corresponding measurements of blood pressure in the conscious animal will be demonstrated.

In multiple fields of study, access to the circulatory system in laboratory studies is necessary. Pharmacological studies in rats using chronically ...

Intranasal Administration of CNS Therapeutics to Awake Mice

Intranasal administration is a method of delivering therapeutic agents to the central nervous system (CNS). It is non-invasive and allows large molecules that do not cross the blood-brain barrier access to the CNS. Drugs are directly targeted to the CNS with intranasal delivery, reducing systemic exposure and thus unwanted systemic side effects1. Delivery from the nose to the CNS occurs within minutes along both the olfactory and trigeminal neural pathways via an extracellular route and does not require drug to bind to any receptor or axonal transport2. Intranasal delivery is a widely publicized method and is currently being used in human clinical trials3.
Intranasal delivery of drugs in animal models allows for initial evaluation of pharmacokinetic distribution and efficacy. With mice, it is possible to administer drugs to awake (non-anesthetized) animals on a regular basis using a specialized intranasal grip. Awake delivery is beneficial because it allows for long-term chronic dosing without anesthesia, it takes less time than with anesthesia, and can be learned and done by many people so that teams of technicians can dose large numbers of mice in short periods. Efficacy of therapeutics administered intranasally in this way to mice has been demonstrated in a number of studies including insulin in diabetic mouse models 4-6 and deferoxamine in Alzheimer's mouse models. 7,8
The intranasal grip for mice can be learned, but is not easy and requires practice, skill, and a precise grip to effectively deliver drug to the brain and avoid drainage to the lung and stomach. Mice are restrained by hand using a modified scruff in the non-dominant hand with the neck held parallel to the floor, while drug is delivered with a pipettor using the dominant hand. It usually takes 3-4 weeks of acclimating to handling before mice can be held with this grip without a stress response. We have prepared this JoVE video to make this intranasal delivery technique more accessible.

A method to intranasally administer drugs to awake mice for the purpose of targeting the brain is described. This method allows for repeat dosing over long periods using intranasal administration of drug without anesthesia, and nose-to-brain delivery with minimal systemic exposure.

Intranasal administration is a method of delivering  therapeutic agents to the central nervous system (CNS). It is  non-invasive and allows large ...

Evaluation of a Novel Laser-assisted Coronary Anastomotic Connector - the Trinity Clip - in a Porcine Off-pump Bypass Model

To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the Trinity Clip, is developed based on the excimer laser-assisted nonocclusive anastomosis technique. The Trinity Clip connector enables simplified, sutureless, and nonocclusive connection of the graft to the coronary artery, and an excimer laser catheter laser-punches the opening of the anastomosis. Consequently, owing to the complete nonocclusive anastomosis construction, coronary conditioning (i.e., occluding or shunting) is not necessary, in contrast to the conventional anastomotic technique, hence simplifying the off-pump bypass procedure. Prior to clinical application in coronary artery bypass grafting, the safety and quality of this novel connector will be evaluated in a long-term experimental porcine off-pump coronary artery bypass (OPCAB) study. In this paper, we describe how to evaluate the coronary anastomosis in the porcine OPCAB model using various techniques to assess its quality. Representative results are summarized and visually demonstrated.

This paper describes a novel nonocclusive coronary anastomotic connector in a porcine off-pump coronary artery bypass (OPCAB) model. This easy-to-use coronary connector has intrinsic potential to facilitate minimally invasive OPCAB surgery.

To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the ...

Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS

The calcineurin inhibitor tacrolimus is the cornerstone of most immunosuppressive treatment protocols after solid organ transplantation in the United States. Tacrolimus is a narrow therapeutic index drug and as such requires therapeutic drug monitoring and dose adjustment based on its whole blood trough concentrations. To facilitate home therapeutic drug and adherence monitoring, the collection of dried blood spots is an attractive concept. After a finger stick, the patient collects a blood drop on filter paper at home. After the blood is dried, it is mailed to the analytical laboratory where tacrolimus is quantified using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in combination with a simple manual protein precipitation step and online column extraction.
For tacrolimus analysis, a 6-mm disc is punched from the saturated center of the blood spot. The blood spot is homogenized using a bullet blender and then proteins are precipitated with methanol/0.2 M ZnSO4 containing the internal standard D2,13C-tacrolimus. After vortexing and centrifugation, 100 &#181;l of supernatant is injected into an online extraction column and washed with 5 ml/min of 0.1 formic acid/acetonitrile (7:3, v:v) for 1 min. Hereafter, the switching valve is activated and the analytes are back-flushed onto the analytical column (and separated using a 0.1% formic acid/acetonitrile gradient). Tacrolimus is quantified in the positive multi reaction mode (MRM) using a tandem mass spectrometer.
The assay is linear from 1 to 50 ng/ml. Inter-assay variability (3.6%-6.1%) and accuracy (91.7%-101.6%) as assessed over 20 days meet acceptance criteria. Average extraction recovery is 95.5%. There are no relevant carry-over, matrix interferences and matrix effects. Tacrolimus is stable in dried blood spots at RT and at +4 &#176;C for 1 week. Extracted samples in the autosampler are stable at +4 &#176;C for at least 72 hr.

Here we describe a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay to quantify the immunosuppressant tacrolimus in dried blood spots using a simple manual protein precipitation step and online column extraction.

The calcineurin inhibitor tacrolimus is the cornerstone of most immunosuppressive treatment protocols after solid organ transplantation in the United ...

Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport

Along with their traditional role as detergents that facilitate fat absorption, emerging literature indicates that bile acids are potent signaling molecules that affect multiple organs; they modulate gut motility and hormone production, and alter vascular tone, glucose metabolism, lipid metabolism, and energy utilization. Changes in fecal bile acids may alter the gut microbiome and promote colon pathology including cholerrheic diarrhea and colon cancer. Key regulators of fecal bile acid composition are the small intestinal Apical Sodium-dependent Bile Acid Transporter (ASBT) and fibroblast growth factor-19 (FGF19). Reduced expression and function of ASBT decreases intestinal bile acid up-take. Moreover, in vitro data suggest that some FDA-approved drugs inhibit ASBT function. Deficient FGF19 release increases hepatic bile acid synthesis and release into the intestines to levels that overwhelm ASBT. Either ASBT dysfunction or FGF19 deficiency increases fecal bile acids and may cause chronic diarrhea and promote colon neoplasia. Regrettably, tools to measure bile acid malabsorption and the actions of drugs on bile acid transport in vivo are limited. To understand the complex actions of bile acids, techniques are required that permit simultaneous monitoring of bile acids in the gut and metabolic tissues. This led us to conceive an innovative method to measure bile acid transport in live animals using a combination of proton (1H) and fluorine (19F) magnetic resonance imaging (MRI). Novel tracers for fluorine (19F)-based live animal MRI were created and tested, both in vitro and in vivo. Strengths of this approach include the lack of exposure to ionizing radiation and translational potential for clinical research and practice.

Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport

Tools to diagnose bile acid malabsorption and measure bile acid transport in vivo are limited. An innovative approach in live animals is described that utilizes combined proton (1H) plus fluorine (19F) magnetic resonance imaging; this novel methodology has translational potential to screen for bile acid malabsorption in clinical practice.

Along with their traditional role as detergents that facilitate fat absorption, emerging literature indicates that bile acids are potent signaling ...

Novel Methods for Intranasal Administration Under Inhalation Anesthesia to Evaluate Nose-to-Brain Drug Delivery

Intranasal administration has been reported to be a potential pathway for nose-to-brain delivery of therapeutic agents that circumvents the blood-brain barrier. However, there have been few reports regarding not only the quantitative analysis but also optimal administration conditions and dosing regimens for investigations of nose-to-brain delivery. The limited progress in research on nose-to-brain pathway mechanisms using rodents represents a significant impediment in terms of designing nose-to-brain delivery systems for candidate drugs.
To gain some headway in this regard, we developed and evaluated two novel methods of stable intranasal administration under inhalation anesthesia for experimental animals. We also describe a method for the evaluation of drug distribution levels in the brain via the nose-to-brain pathway using radio-labeled [14C]-inulin (molecular weight: 5,000) as a model substrate of water-soluble macromolecules.
Initially, we developed a pipette-based intranasal administration protocol using temporarily openable masks, which enabled us to perform reliable administration to animals under stable anesthesia. Using this system, [14C]-inulin could be delivered to the brain with little experimental error.
We subsequently developed an intranasal administration protocol entailing reverse cannulation from the airway side through the esophagus, which was developed to minimize the effects of mucociliary clearance (MC). This technique led to significantly higher levels of [14C]-inulin, which was quantitatively detected in the olfactory bulb, cerebrum, and medulla oblongata, than the pipette method. This appears to be because retention of the drug solution in the nasal cavity was substantially increased by active administration using a syringe pump in a direction opposite to the MC into the nasal cavity.
In conclusion, the two methods of intranasal administration developed in this study can be expected to be extremely useful techniques for evaluating pharmacokinetics in rodents. The reverse cannulation method, in particular, could be useful for evaluating the full potential of nose-to-brain delivery of drug candidates.

Here, we describe two novel methods of stable intranasal administration under inhalation anesthesia with minimal physical stress for experimental animals. We also describe a method for quantitative evaluation of drug distribution levels in the brain via the nose-to-brain pathway using radiolabeled [14C]-inulin as a model substrate of water-soluble macromolecules.

Intranasal administration has been reported to be a potential pathway for nose-to-brain delivery of therapeutic agents that circumvents the blood-brain ...

Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice

Isoproterenol (ISO), is a non-selective beta-adrenergic agonist, that is used widely to induce cardiac injury in mice. While the acute model mimics stress-induced cardiomyopathy, the chronic model, administered through an osmotic pump, mimics advanced heart failure in humans. The purpose of the described protocol is to create the chronic ISO-induced heart failure model in mice using an implanted mini-pump. This protocol has been used to induce heart failure in 100+ strains of inbred mice. Techniques on surgical pump implantation are described in detail and may be relevant to anyone interested in creating a heart failure model in mice. In addition, the weekly cardiac remodeling changes based on echocardiographic parameters for each strain and expected time to model development are presented. In summary, the method is simple and reproducible. Continuous ISO administered via the implanted mini-pump over 3 to 4 weeks is sufficient to induce cardiac remodeling. Finally, the success for ISO model creation may be assessed in vivo by serial echocardiography demonstrating hypertrophy, ventricular dilation, and dysfunction.

The chronic administration of isoproterenol via an implanted osmotic pump has been used widely to mimic advanced heart failure in mice. Here, we describe detailed methods in surgical mini-pump implantation for the continuous isoproterenol administration over 3 weeks, as well as, echocardiographic assessment for the successful model creation.

Isoproterenol (ISO), is a non-selective beta-adrenergic agonist, that is used widely to induce cardiac injury in mice. While the acute model mimics ...

Evaluation of Cerebral Blood Flow Autoregulation in the Rat Using Laser Doppler Flowmetry

When investigating the body&#39;s mechanisms for regulating cerebral blood flow, a relative measurement of microcirculatory blood flow can be obtained using laser Doppler flowmetry (LDF). This paper demonstrates a closed skull preparation that allows cerebral blood flow to be assessed without penetrating the skull or installing a chamber or cerebral window. To evaluate autoregulatory mechanisms, a model of controlled blood pressure reduction via graded hemorrhage can be utilized while simultaneously employing LDF. This enables the real time tracking of the relative changes in the blood flow in response to reductions in arterial blood pressure produced by the withdrawal of circulating blood volume. This paradigm is a valuable approach to study cerebral blood flow autoregulation during reductions in arterial blood pressure and, with minor modifications in the protocol, is also valuable as an experimental model of hemorrhagic shock. In addition to evaluating autoregulatory responses, LDF can be used to monitor the cortical blood flow when investigating metabolic, myogenic, endothelial, humoral, or neural mechanisms that regulate cerebral blood flow and the impact of various experimental interventions and pathological conditions on cerebral blood flow.

This article demonstrates the use of laser Doppler flowmetry to evaluate the ability of the cerebral circulation to autoregulate its blood flow during reductions in arterial blood pressure.

When investigating the body&#39;s mechanisms for regulating cerebral blood flow, a relative measurement of microcirculatory blood flow can be obtained ...

Intratracheal Administration of Dry Powder Formulation in Mice

In the development of inhalable dry powder formulations, it is essential to evaluate their biological activities in preclinical animal models. This paper introduces a noninvasive method of intratracheal delivery of dry powder formulation in mice. A dry powder loading device that consists of a 200 &#181;L gel loading pipette tip connected to an 1 mL syringe via a three-way stopcock is presented. A small amount of dry powder (1-2 mg) is loaded into the pipette tip and dispersed by 0.6 mL of air in the syringe. Because pipette tips are disposable and inexpensive, different dry powder formulations can be loaded into different tips in advance. Various formulations can be evaluated in the same animal experiment without device cleaning and dose refilling, thereby saving time and eliminating the risk of cross-contamination from residual powder. The extent of powder dispersion can be inspected by the amount of powder remaining in the pipette tip. A protocol of intubation in mouse with a custom-made light source and a guiding cannula is included. Proper intubation is one of the key factors that influences the intratracheal delivery of dry powder formulation to the deep lung region of the mouse.

Dry powder formulations for inhalation have great potential in treating respiratory diseases. Before entering human studies, it is necessary to evaluate the efficacy of the dry powder formulation in preclinical studies. A simple and noninvasive method of the administration of dry powder in mice through the intratracheal route is presented.

In the development of inhalable dry powder formulations, it is essential to evaluate their biological activities in preclinical animal models. This paper ...

The Intra-Aortic Balloon Pump

Cardiogenic shock remains one of the most challenging clinical syndromes in modern medicine. Mechanical support is being increasingly used in the management of cardiogenic shock. Intra-aortic balloon pump (IABP) is one of the earliest and most widely used types of mechanical circulatory support. The device acts by external counterpulsation and uses systolic unloading and diastolic augmentation of aortic pressure to improve hemodynamics. Although IABP provides less hemodynamic support when compared with newer mechanical circulatory support devices, it can still be the mechanical support device of choice in appropriate situations because of its relative simplicity of insertion and removal, need for smaller size vascular access and better safety profile. In this review, we discuss the equipment, procedural and technical aspects, hemodynamic effects, indications, evidence, current status and recent advances in the use of IABP in cardiogenic shock.

We describe the steps for the percutaneous implantation of the intra-aortic balloon pump (IABP), a mechanical circulatory support device. It acts by counterpulsation, inflating at the onset of diastole, augmenting diastolic aortic pressure and improving coronary blood flow and systemic perfusion, and deflating before systole, reducing left ventricular afterload.