Skip to content

Melanin and Dermal Uptake of Thirdhand Cigarette Smoke

Melanin and Dermal Uptake of Thirdhand Cigarette Smoke

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06020248
Acronym
THS05
Enrollment
60
Registered
2023-08-31
Start date
2023-09-01
Completion date
2026-11-01
Last updated
2026-06-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

Thirdhand tobacco smoke, Dermal, Exposure, Tobacco Smoke Pollution, Melanin, Nicotine

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.

Interventions

OTHERWear clothing that has been exposed to cigarette smoke for 3 hours.

Cotton clothing is exposed to smoke from Marlboro Red (hard pack) cigarettes at 1-1.2 mg/m3 repeatedly, until total exposure equals 3 grams total particulate material. When tested after exposure, the clothing typically contained 59.15 +/- 18 µg nicotine and 42 +/- 24 ng NNK per gram. The mass of the clothing varies by size, but the average combination of pants and shirt contains 32 mgs nicotine and 23 µg NNK.

Sponsors

University of California, San Francisco
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE

Masking description

Smoke exposure is impossible to mask and team is too small to mask data analysis until later stages.

Intervention model description

Dermal uptake, metabolism and excretion of nicotine in participants with high and low levels of dermal melanin will be compared.

Eligibility

Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Change in blood concentrations of nicotineBaseline and 3 hoursThe 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-hydroxycotinineFirst void, collected for 10 daysThe 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

MeasureTime frameDescription
Urinary concentration of the NNK metabolite NNALFirst void, collected for 10 daysThe 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.

Countries

United States

Contacts

CONTACTSuzaynn F Schick, PhD
suzaynn@gmail.com415-514-3535
CONTACTAbel Huang, BS
abel.huang@ucsf.edu(415) 514-9011
PRINCIPAL_INVESTIGATORSuzaynn F Schick, PhD

University of California, San Francisco

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 17, 2026