The effects of Tween-80 on the integrity of solutions of capsaicin: useful information for performing tussigenic challenges

Kopec, Scott; Irwin, Richard S.; DeBellis, Ronald J.; Böhlke, Mark; Maher, Timothy J.

doi:10.1186/1745-9974-4-3

Cited by 11 publications

(14 citation statements)

References 13 publications

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“…The dosage and measurement period were determined in pilot studies. The capsaicin (M2028; Sigma-Aldrich Chemie GmbH, Germany) had been diluted in 96% ethanol for titration, dried and made up in a sterile solution of 0.9% saline and Tween 80 (P1754-500; Sigma-Aldrich Chemie GmbH) at 60°C according to Kopec et al (2008) to ensure even distribution and accurate dosing. All instrumentation was removed and snakes were housed and fed normally for 1 month between trials.…”

Section: Sedation and Capsaicin Stimulationmentioning

confidence: 99%

Tachycardia in response to remote capsaicin injection as a model for nociception in the ball python (Python regius)

Williams

James

Bertelsen

et al. 2016

Veterinary Anaesthesia and Analgesia

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Section: Sedation and Capsaicin Stimulationmentioning

confidence: 99%

Tachycardia in response to remote capsaicin injection as a model for nociception in the ball python (Python regius)

Williams

James

Bertelsen

et al. 2016

Veterinary Anaesthesia and Analgesia

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“…The investigation employs a more than 99% pure pharmaceutical grade capsaicin via an Investigational New Drug (IND 69,642) submission [21]. A Registered Pharmacist mixes individual pharmaceutical grade capsaicin doses because purity and solubility are essential qualities for the capsaicin stock solution and are prerequisites for accurate dilute capsaicin doses [5,[22][23][24]. Analyses of prepared capsaicin solutions are by high performance liquid chromatography (HPLC); other investigators employ ultraviolet absorption spectrophotometry to determine capsaicin concentrations [22].…”

Section: Discussionmentioning

confidence: 99%

Laboratory Safety of Capsaicin Inhalation in Healthy Younger and Older Populations Potential Template for Inhalation Research

Brooks¹,

Truncale²,

Sams³

2016

J Allergy Ther

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Introduction: There are inconsistencies as to the effects of age on the human cough reflex. The investigation speaks to the Federal Drug Agency's (FDA) trepidations for conducting inhalation experiments with non-approved medications/chemicals. The investigation addresses the accuracy of the mixing methodology and analysis of capsaicin stability during seven months of storage. Methods: There is stringent safety monitoring while conducting 12 serial (0.49-1000 uMol) single breath capsaicin inhalation challenge testing (CICT) on 20 younger and 20 older healthy research volunteers using pharmaceutical-grade capsaicin (i.e., Investigational New Drug protocol-IND 69,642). The research design and subject safety measures are recommended by the Food & Drug Agency (FDA) and approved by the Institutional Review Board (IRB). Mixing of inhaled capsaicin solutions are by a Registered Pharmacist and concentration verifications are by high performance liquid chromatography (HPLC). Potency of stored capsaicin (i.e., refrigerated and shielded from UV light) is examined over 7 months. Results: There are neither adverse reactions nor statistically significant difference in capsaicin cough parameters for older and younger volunteers at any dose of capsaicin. Physiologic monitoring by spirometry, impulse oscillometry, exhaled breath nitric oxide, electrocardiography, blood pressure, pulse and oxygen saturation measurements do not change at any dose. There are differences between the concentrations of capsaicin solutions mixed by a Registered Pharmacist and actual capsaicin determination by HPLC. The differences in capsaicin concentrations are 28.1% lower for 0.49 uMol compared to a 2.2% lesser concentration for 1000 uMol solution. During storage, capsaicin remains stable for 3-months but substantially falls by six (p<0.03) and seven (p<0.004) months, especially for the lower concentrations. Conclusion: The results of this investigation embrace the safety of serial Inhalations of dilute pharmacologic grade capsaicin aerosol among older and younger normal volunteers. Incorporating rigorous FDA recommendations, inclusion of IRB oversight and monitoring by spirometry, impulse oscillometry, exhaled breath nitric oxide, electrocardiography, blood pressure, pulse and oxygen saturation measurements document inhalation safety at any dilute capsaicin aerosol dose. However, there are lower capsaicin values determined by HPLC compared to expected capsaicin concentrations when mixed by a Registered Pharmacist or after six months of storage. The investigation champions the opinion that inhalation studies involving FDA non-approved drugs or chemicals/ medications can be safely conducted when following the appropriate safety procedures such as in this research protocol.

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“…Studies reported by Kopec et al [ 6 , 7 ]. provided the groundwork for this study of CAP solutions involving the use of Tween as a solvent.…”

Section: Discussionmentioning

confidence: 99%

“…Since subjects are required to inhale CAP solutions for an extended period of time, the taste of the solutions begins to cause discomfort. Although previous studies reported quantitative comparisons of CAP in solutions with Tween versus solutions without Tween [ 6 , 7 ], to the authors’ knowledge, there has yet to be a study that directly compares the solubility of a broad range of concentrations of CAP in 10% EtOH alone to CAP in a Tween solution. Furthermore, a comparison of CAP solubility in solutions of varying percentages of EtOH has yet to be reported.…”

Section: Introductionmentioning

confidence: 99%

Standardized method for solubility and storage of capsaicin-based solutions for cough induction

Costanzo

Yost

Davenport

2014

Cough

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BackgroundPreparation of inhaled capsaicin solutions for cough induction varies greatly from one lab to another, which creates inconsistencies between tussigenic challenge results. The addition of Tween to these capsaicin solutions provides increased solubility and stability; however, the foul taste of Tween makes inhaling the solution for any prolonged period of time unpleasant. We sought to create a standard method for preparing soluble and stable capsaicin-based solutions (in 10% ethanol/water), without the addition of Tween.MethodsCapsaicin solutions were created at concentrations ranging from 0 to 500 μM in a variety of solvent systems, with and without Tween. Samples were stored in four different environments (-20°C, 3°C, and room temperature, protected from light; and room temperature, exposed to light) to test stability. Detection of capsaicin was carried out by UV absorption. A Grubb’s test was performed on all data to remove statistical outliers.ResultsSimilar capsaicin concentrations were seen for solutions prepared with or without Tween (Tween provided a slight increase in solubility), with neither solvent system providing complete solubility. Of the four environments tested, storing capsaicin solutions at 3°C while protected from light afforded the greatest stability, for a minimum of 30 weeks.ConclusionWe recommend the use of a 10% ethanol/water solvent system without Tween in the preparation of capsaicin solutions for tussigenic challenges. While this solvent system does not provide complete solubility, we have detailed a method for capsaicin solution preparation that will account for this loss of solubility, while maintaining a solution that is Tween-free and safe for human inhalation.

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The effects of Tween-80 on the integrity of solutions of capsaicin: useful information for performing tussigenic challenges

Abstract: Background: Because variable results of capsaicin challenges may be due to the incomplete solubility of capsaicin, we sought to determine if the use of Tween-80 in solutions of capsaicin improves actual concentrations of freshly prepared and stored solutions.

Cited by 11 publications

References 13 publications

Tachycardia in response to remote capsaicin injection as a model for nociception in the ball python (Python regius)

Tachycardia in response to remote capsaicin injection as a model for nociception in the ball python (Python regius)

Laboratory Safety of Capsaicin Inhalation in Healthy Younger and Older Populations Potential Template for Inhalation Research

Standardized method for solubility and storage of capsaicin-based solutions for cough induction

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