NCT07442591

A Study to Assess Effect of Dosing Intervals on Multiple-Dose Pharmacokinetics of WD-1603 Taken Before Meals in Healthy Participants

A Clinical Study to Assess the Effect of Different Dosing Intervals on the Multiple-Dose Pharmacokinetics of WD-1603 (25mg Carbidopa/150mg Levodopa) When Administered Before Meals in Healthy Participants

• Status: Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 12 (estimated)
• Sponsor: Shanghai WD Pharmaceutical Co., Ltd. · Industry
• Sex: All
• Age: 18 Years – 55 Years
• Healthy volunteers: Accepted

Summary

WD-1603 contains two different drugs called levodopa and carbidopa in one tablet. The goal of this clinical trial is to see if taking the study drug WD-1603 at different time intervals affects how the drug acts in healthy volunteers. We also want to learn about the safety of WD-1603. The main question we want to answer is: * How does the body process WD-1603 when it is taken by different time intervals? What will participants do? * Participants will take one tablet of WD-1603 twice a day on three separate days. * On each dosing day, the two doses will be spaced different hours apart. * Between each dosing day, there will be a rest period of up to 7 days.

Detailed description

This trial is a multiple-dose, open-label, sequential, three-period pharmacokinetic study comparing different dosing intervals of WD-1603 in healthy participants. The purpose of the study is: * To evaluate the effect of different dosing intervals on the pharmacokinetics of twice-daily WD-1603 when administered before meals. * To assess the safety and tolerability of WD-1603 in healthy participants. Each participant will receive the investigational drug in the sequence of Treatment A, Treatment B, and Treatment C. After each dosing period, there will be a washout period of up to 7 days. This Phase I clinical trial is planned to enroll 12 healthy participants, with an appropriate proportion of female participants (at least one quarter, i.e., 3 participants). Pharmacokinetic parameters will be calculated using Phoenix WinNonlin (version 8.3 or higher), and other analyses will be performed using SAS software (version 9.4 or higher). Using PKS, an analysis of variance (ANOVA) is performed on the natural log-transformed Cmax, AUC0-τ, and ΔC0.5. The model includes dosing occasion as a fixed effect and participant as a random effect. The 90% confidence interval for the geometric mean ratio (second dose/first dose) of each parameter is calculated.

Conditions

• Healhty

Interventions

Type	Name	Description
DRUG	Carbidopa and Levodopa Controlled-Release Tablets (25 mg/150 mg)	Administered twice daily for one day with a 5-hour interval between doses.
DRUG	Carbidopa and Levodopa Controlled-Release Tablets (25 mg/150 mg)	Administered twice daily for one day with a 6-hour interval between doses.
DRUG	Carbidopa and Levodopa Controlled-Release Tablets (25 mg/150 mg)	Administered twice daily for one day with a 7-hour interval between doses.

Timeline

• Start date: 2026-03-24
• Primary completion: 2026-06-01
• Completion: 2026-12-01
• First posted: 2026-03-02
• Last updated: 2026-04-08

Locations

1 site across 1 country: China

Regulatory

• FDA-regulated drug study