Melanin and Dermal Uptake of Thirdhand Cigarette Smoke

Not Applicable

Not yet recruiting

• Conditions: Healthy
• Interventions: Other: Wear clothing that has been exposed to cigarette smoke for 3 hours.

• Registration Number: NCT06020248
• Lead Sponsor: University of California, San Francisco

Brief Summary

This is a pilot study of the effects of dermal melanin on dermal uptake and retention of nicotine. The initial hypothesis is that higher levels of dermal melanin will correlate with lower uptake and longer retention of nicotine in the skin and body.

Detailed Description

This is an interventional pharmacokinetic study comparing the uptake and metabolism of nicotine from smoke-exposed clothing in people with low high levels of dermal melanin and people with high levels of dermal melanin. The study will measure nicotine and metabolites of nicotine in the blood during exposure and in urine for 10 days after exposure.

Study Timeline

• Study First Submitted: 2023-08-25
• Study First Submitted QC: 2023-08-25
• Study First Posted: 2023-08-31
• Status Verified: 2023-09
• Study Start: 2023-09
• Last Update Submitted: 2023-09-01
• Last Update Posted: 2023-09-06
• Primary Completion: 2025-11
• Study Completion: 2025-11

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Adult nonsmoker
• Aged 18-50
• Skin reflectance scores below 150 or above 249 using the Mexameter 18 instrument
• Healthy on the basis of medical history
• Systolic blood pressure <150
• Diastolic blood pressure <100
• C-reactive protein <3.1 mg/ml
• Liver function (AST and ALT) in normal ranges
• kidney function (BUN) in normal ranges
• LDL<131
• Blood glucose <110
• Not exposed to tobacco SHS.

Exclusion Criteria

• Dermal skin reflectance score between 150 and 249, as measured by the Mexameter 18 instrument.
• Positive SARS-CoV-2 antibody test
• Age 18 < or > 50
• Physician diagnosis of asthma, heart disease, hypertension, thyroid disease, diabetes, renal or liver impairment or glaucoma.
• Unstable psychiatric condition (such as current major depression, history of schizophrenia or bipolar disorder) or current use of more than two psychiatric medications
• Systolic blood pressure greater than or equal to 150
• Diastolic blood pressure greater than or equal to 100
• Blood glucose greater than or equal to 110
• LDL greater than or equal to130
• Pregnancy or breastfeeding (by urine hCG and/or history)
• Alcohol or illicit drug dependence within the past 5 years
• BMI > 35 and < 18
• Current illicit drug use (by history or urine test)
• More than 1 pack year smoking history
• Ever a daily marijuana smoker
• Smoked anything within the last 3 months
• Unable to hold allergy or other OTC medicines
• Occupational exposure to smoke, dusts OR fumes
• Concurrent participation in another clinical trial
• Unable to communicate in English
• No social security number

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
High melanin	Wear clothing that has been exposed to cigarette smoke for 3 hours.	Individuals with skin reflectance scores above 249 using the Mexameter 18 instrument
Low melanin	Wear clothing that has been exposed to cigarette smoke for 3 hours.	Individuals with skin reflectance scores below 150 using the Mexameter 18 instrument.

Primary Outcome Measures

Name	Time	Method
Change in blood concentrations of nicotine	Baseline and 3 hours	The study will measure concentration of nicotine in the blood before and after the dermal exposure to nicotine.
Total combined urinary concentrations of the nicotine metabolites cotinine and 3-hydroxycotinine	First void, collected for 10 days	The study will measure urinary metabolites of nicotine in the first void of the day for 10 days after exposure and sum the total mass of metabolites.

Secondary Outcome Measures

Name	Time	Method
Urinary concentration of the NNK metabolite NNAL	First void, collected for 10 days	The study will measure urinary metabolites of NNK in the first void of the day for 10 days after exposure and sum the total mass of metabolites.

Trial Locations

Locations (1)

Zuckerberg San Francisco General Hospital; 🇺🇸 San Francisco, California, United States