Effect of Double Nutri® Liposomal Encapsulation Technology on Human Absorption of Vitamin C and Glutathione Liquid Sachet

The objective of this study is to evaluate whether Double Nutri® liposomal encapsulation technology can enhance the oral absorption of liquid vitamin C and glutathione supplements in humans.

Study Overview

• Status: Completed
• Conditions: Glutathione; Vitamin C
• Intervention / Treatment: Dietary supplement: Vitamin C and Glutathione without liposome; Dietary supplement: Liposomal Vitamin C and Glutathione

Detailed Description

This study is a single-center, self-controlled crossover human trial designed to evaluate the differences in blood concentration changes and bioavailability following a single oral dose of liquid vitamin C and glutathione supplements.

Healthy adult participants aged 18 years and older will be enrolled. Each participant will complete two study sessions, with a minimum washout period of 7 days between sessions. On each study day, venous blood samples will be collected prior to test product administration (0 minutes) to assess vitamin C levels, glutathione levels, complete blood count, blood lipids, blood glucose, and liver and kidney function indicators.

After baseline blood collection, a standardized breakfast will be provided and consumed within 10 minutes, followed by administration of the test product. Venous blood samples will then be collected at 0.5, 1, 2, 4, 6, and 8 hours post-intake to measure vitamin C and glutathione concentrations. Lunch will be provided after the 4-hour blood draw, and dinner will be provided after the 8-hour blood draw. Identical meals will be provided during both study sessions.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Taiwan
  • Taipei, Taiwan, 114
    • TCI Co., Ltd

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 18 years or older, of any sex, who are willing to sign the informed consent form and are able to fully comply with all study procedures.

Exclusion Criteria:

• Pregnant or breastfeeding women, or individuals unwilling to use physical contraceptive methods during the study period, such as condoms or intrauterine devices (IUDs).
• Employees of TCI Co., Ltd and their family members.
• Individuals who, within 30 days prior to study initiation, have been taking vitamin C supplements at doses greater than 200 mg per day, glutathione supplements at doses greater than 100 mg per day, or medications that may affect endogenous vitamin C or glutathione levels, such as oral contraceptives and estrogen preparations (including ethinylestradiol, desogestrel, gestodene, drospirenone, cyproterone acetate), or acetaminophen.
• Individuals with chronic gastrointestinal diseases (including irritable bowel syndrome [IBS], inflammatory bowel disease [IBD], chronic diarrhea, Crohn's disease, celiac disease, bowel control disorders/fecal incontinence, pancreatitis, peptic ulcer disease, colorectal cancer, short bowel syndrome, and ulcerative colitis), a history of epilepsy or seizures, liver or kidney disease, malignancy, endocrine disorders, psychiatric disorders, alcohol or drug abuse, or other significant organic diseases based on medical history.
• Individuals who have undergone gastrointestinal surgery, organ transplantation, or other major surgical procedures.
• Individuals who experienced acute gastroenteritis within two weeks prior to study initiation.
• Individuals with a known allergy to any components of the testing samples.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Vitamin C and Glutathione without liposome; Each administration consists of two sachets, with each sachet containing 1,000 mg of vitamin C and 60 mg of glutathione	Dietary supplement: Vitamin C and Glutathione without liposome; Each administration consists of two sachets, with each sachet containing 1,000 mg of vitamin C and 60 mg of glutathione.
Experimental: Liposomal Vitamin C and Glutathione; Each administration consists of two sachets, with each sachet containing 1,000 mg of vitamin C and 60 mg of glutathione, and the test sample is processed using the Double Nutri liposomal technology	Dietary supplement: Liposomal Vitamin C and Glutathione; Each administration consists of two sachets, with each sachet containing 1,000 mg of vitamin C and 60 mg of glutathione, and the product is processed using the Double Nutri liposomal technology.; Other Names: GLUTA BRIGHT; Double Nutri Vitamin C and Glutathione

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood vitamin C level (ug/mL)	Blood vitamin C levels will be measured at fasting and at 0.5, 1, 2, 4, 6, and 8 hours post-intake.	at 8 hours after taking test sample
Blood glutathione level (μmol/L)	Whole blood glutathione levels will be measured at fasting and at 0.5, 1, 2, 4, 6, and 8 hours post-intake.	at 8 hours after taking test sample

Collaborators and Investigators

• Sponsor: TCI Co., Ltd.
• Investigators: Principal Investigator: Tong-Lin Wu, TCI Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): December 15, 2025
• Primary Completion (Actual): January 16, 2026
• Study Completion (Actual): February 2, 2026

Study Registration Dates

• First Submitted: December 11, 2025
• First Submitted That Met QC Criteria: December 11, 2025
• First Posted (Actual): December 24, 2025

Study Record Updates

• Last Update Posted (Actual): February 3, 2026
• Last Update Submitted That Met QC Criteria: February 2, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: vitamin c; liposomal; glutathione; Double Nutri; human bioavailability
• Additional Relevant MeSH Terms: Peptides; Amino Acids, Peptides, and Proteins; Oligopeptides; Organic Chemicals; Pharmaceutical Preparations; Dosage Forms; Carbohydrates; Sugar Acids; Acids, Acyclic; Carboxylic Acids; Hydroxy Acids; Biomedical and Dental Materials; Manufactured Materials; Technology, Industry, and Agriculture; Membranes, Artificial; Drug Carriers; Biomimetic Materials; Ascorbic Acid; Liposomes; Glutathione
• Other Study ID Numbers: 25-098-A

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No