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Completed

NCT Number: NCT01963910

Double-blind Trial of Mannitol Cream to Block the Effect of Capsaicin Cream

Capsaicin is a TRPV1 (transient receptor potential vanilloid 1) agonist, causing pain upon application. The investigators wish to determine whether mannitol blocks the effect of capsaicin application. As both cream bases are identical and mannitol addition is the only difference between the creams, if the mannitol cream is more effective in blocking the effect of capsaicin on the TRPV1 (transient receptor potential vanilloid 1) receptor, the investigators will have established that mannitol down-regulates or blocks the TRPV1 (transient receptor potential vanilloid 1) receptor.

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Key information

Conditions

Pain Nervous System Diseases Neuralgia Neurologic Manifestations Neuromuscular Diseases Pathological Conditions, Signs and Symptoms Peripheral Nervous System Diseases Signs and Symptoms

Age range

19 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Dr. Helene Bertrand Inc., 220-1940 Lonsdale Ave.

North Vancouver, British Columbia, V7M 2K2, Canada

About this study

Capsaicin cream, which stimulates the TRPV1 (transient receptor potential vanilloid 1) receptor, causing a burning sensation, will be applied to both halves of the upper lip until a burning sensation with 8/10 intensity on an NRS (Visual Analog Scale) scale is experienced or five minutes have elapsed. Following this, the capsaicin cream will be wiped off and 30% mannitol in vehicle cream ( isopropyl palmitate, caprylic capric triglyceride, propylene glycol, ceteareth 20, cetearyl alcohol, glyceryl stearate, polyethylene glycol 100 stearate, dimethicone, octyldodecanol, lecithin, ethylhexyl glycerin and phenoxy ethanol) will be applied to one half of the upper lip, and vehicle cream alone will be applied to the other half. Cream assignment will be randomized and neither the subject nor the person applying the cream will know which half upper lip has which cream. Every minute for 10 minutes, the heat sensation felt in each half upper lip will be measured, using a visual scale from 0 to 10. A repeated measures analysis of variance will compare the NRS (Visual Analog Scale) scores from the 30% mannitol cream, to the NRS (Visual Analog Scale)scores from the vehicle cream. Significance will be accepted if P less than .05.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age between 19 and 80 years

Exclusion criteria

  • Diet containing capsaicin (Cayenne pepper, capsicum) (spicy foods), more than once a week.
  • Meal containing capsaicin (spicy foods) within 5 days prior to the experiment.
  • Any lesion, cracking, cold sore or abrasion on the lips
  • Inability to tolerate capsaicin containing "spicy foods"
  • Wearing lipstick or lip balm on the upper lip
  • Inability to fill out an NRS pain scale
  • Use of painkilling medication, within 24 hours of the study.
  • Allergy to any of the ingredients of the creams, or to mannitol
  • History of contact or allergic dermatitis
  • Pregnant or nursing women

Treatment and study plan

30% Mannitol in vehicle cream

Drug

applied to one half of the upper lip following removal of capsaicin cream.

Other names: mannitol cream, Mannitol, mannite, manna sugar, C6H8(OH)6

Vehicle cream

Drug

application to the other half of the upper lip following capsaicin cream removal

Primary outcomes

  1. NRS heat score, once per minute

    Time frame: 15 minutes per subject

    Every minute after capsaicin cream application, subject will indicate NRS (numerical rating scale)heat score. When the score has reached 8/10 or after five minutes, the cream will be removed. The time needed to reach 8/10 heat score and the heat score achieved, or the score at five minutes will be recorded. Following application of the test creams, NRS (Visual Analog Scale) heat scores will be recorded once per minute for each side for 10 minutes.

Secondary outcomes

  1. Side effects of capsaicin cream on upper lip

    Time frame: One hour

    The subject will be observed for redness, swelling, or other side effects following the capsaicin cream application. These side effects will be recorded

Other outcomes

  1. Side effects of test creams

    Time frame: one hour

    The subjects will be observed for side effects of the mannitol cream or the vehicle cream

Sponsors and collaborators

Lead sponsor

University of British Columbia

Other

Registry information

Acronym: LipTRP

Important dates

Study start
2013
Primary completion
2014
Study completion
2014
First posted
Oct 16, 2013
Registry last updated
Mar 4, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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