Recruiting
Early Phase 1

Curcumin with Diclofenac

Sponsor:

Washington State University

Code:

NCT06053411

Conditions

Interaction

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Interventions

Diclofenac

curcumin

Study Details

Brief summary:

The purpose of this pilot study is to gather preliminary data on the (1) contribution of the understudied drug metabolizing enzyme, UDP-glucuronosyltransferase (UGT) 2B17, to the metabolism of a widely used medication, diclofenac, and (2) impact of the UGT2B17 inhibitor and natural product, curcumin, on diclofenac pharmacokinetics. Results will inform future studies aimed to assess the effects of UGT2B17 genetic polymorphisms and co-consumed xenobiotics on the pharmacokinetics and toxicity risk of diclofenac and other UGT2B17 drug substrates.

Conditions

Interaction

Study ID

NCT06053411

Start date

Mar 1, 2024

Status verified date

Jun, 2026

Completion date

Dec 18, 2026

Anticipated

Primary completion date

Aug 18, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Aged from 18-64 years and healthy
  • Not taking any medications (prescription and non-prescription) or dietary/herbal supplements known to alter the pharmacokinetics of diclofenac or curcumin
  • Willing to abstain from consuming caffeinated beverages or other caffeine-containing products the evening before and morning of the first day of each study arm
  • Willing to abstain from consuming any alcoholic beverages for one day prior to any study day, during the 14-hour inpatient days, and for the outpatient visit(s) following the 14-hour days
  • Willing to use a secondary method of birth control that does not include the introduction or discontinuance of hormonal-based birth control (such as abstinence, copper IUD, or condoms)
  • Have the time to participate
  • Written informed consent (and assent when applicable) obtained from subject or subject's legal representative and ability for the subject to comply with the requirements of the study

Exclusion Criteria:

  • Under the age of 18 or over the age of 65 years
  • Smoke/vape/chew tobacco products
  • Use cannabis products, including marijuana, hemp, and other THC- or CBD-containing products
  • Have any current major illness or chronic illness such as (but not limited to) kidney disease, hepatic disease, diabetes mellitus, hypertension, coronary artery disease, chronic obstructive pulmonary disease, cancer, or HIV/AIDS
  • History of anemia or any other significant hematologic disorder
  • History of drug or alcohol addiction or major psychiatric illness
  • Pregnant or nursing or plan to become pregnant within 3 weeks after participation
  • History of allergy intolerance to diclofenac or curcumin
  • Taking concomitant medications, both prescription and non-prescription (including dietary supplements/herbal products), known to alter the pharmacokinetics of diclofenac or curcumin
  • Taking any turmeric spice or curcumin supplement
  • Presence of a condition or abnormality that, in the opinion of the Investigator, would compromise participant safety or quality of the data
  • Out-of-range clinical laboratory value that the study physician considers participation in the study a health risk

Study Design

Enrollment

30 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Arm 1: diclofenac alone (baseline)

A single dose of diclofenac (25 mg capsule) will be administered by mouth to 5 participants (minimum 2 females) genotyped as extensive metabolizers (Arm 1A) and 5 participants (minimum 2 females) genotyped as poor metabolizers (Arm 1B). Plasma and urine will be collected from 0-12 hours. A washout of at least 3 days will elapse between Arm 1 and Arm 2.

experimental: Arm 2: diclofenac + curcumin

A single oral dose of diclofenac (25 mg capsule) and a single oral dose of curcumin (2,000 mg tablet) will be administered by mouth to the 5 participants genotyped as extensive metabolizers. Plasma and urine will be collected from 0-12 hours.

Interventions

Diclofenac

25 mg capsule

curcumin

2,000 mg tablet

Primary outcome measure

  • Diclofenac area under the concentration vs. time curve (AUC) in UGT2B17 extensive metabolizers (EMs) [ Time Frame: 0-12 hours ]
  • Diclofenac AUC in poor metabolizers (PMs) [ Time Frame: 0-12 hours ]
  • Diclofenac AUC in EMs in the presence of curcumin [ Time Frame: 0-12 hours ]
  • Diclofenac maximum concentration (Cmax) in EMs [ Time Frame: 0-12 hours ]
  • Diclofenac Cmax in PMs [ Time Frame: 0-12 hours ]
  • Diclofenac Cmax in EMs in the presence of curcumin [ Time Frame: 0-12 hours ]
  • Diclofenac renal clearance (CLr) in EMs [ Time Frame: 0-12 hours ]
  • Diclofenac CLr in PMs [ Time Frame: 0-12 hours ]
  • Diclofenac CLr in EMs in the presence of curcumin [ Time Frame: 0-12 hours ]
  • Diclofenac half-life (t1/2) in EMs [ Time Frame: 0-12 hours ]
  • Diclofenac half-life (t1/2) in PMs [ Time Frame: 0-12 hours ]
  • Diclofenac half-life (t1/2) in EMs in the presence of curcumin [ Time Frame: 0-12 hours ]

Central Contacts and Locations

Central contacts

Mary F Paine, RPh, PhD

509-358-7759mary.paine@wsu.edu

Siavosh Naji-Talakar, PharmD, MS

509-358-7739s.naji-talakar@wsu.edu

Locations

Washington State University College of Pharmacy and Pharmaceutical Sciences

Recruiting

Spokane, Washington, United States, 99202

Contacts

Mary F Paine, RPh, PhD

509-358-7759mary.paine@wsu.edu

Deena Hadi, BS

509-368-6692deena.hadi@wsu.edu

Principal Investigator:

Mary F Paine, RPh, PhD

More Information

Sponsor

Washington State University

Last update posted

Jun 4, 2026

Last verified

Jun, 2026

Keywords

  • Pharmacokinetic

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Washington State University on 2026-06-04.