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Session: Carotenoids and Retinoids in Focus: Insights into Delivery, Vision, and Disease Prevention (Oral 8)

(OR08-07-24) Evaluation of Vitamin A Capsule Stability and Single-Use Syringes to Increase Accessibility of Dose-Response Tests for Status Assessment

Sunday, June 30, 2024
9:12 AM – 9:24 AM CT
Location:  W183

    Presenting Author(s)

  • KT

    Khushi Tanna

    Undergraduate Student
    University of Wisconsin-Madison
    Germantown, Wisconsin, United States

    Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

    • Co-Author(s)

  • MF

    Molly Fjalstad

    University of Wisconsin-Madison, United States

  • BG

    Bryan M. Gannon, PhD (he/him/his)

    Scientist
    University of Wisconsin-Madison
    Madison, Wisconsin, United States

  • ST

    Sherry A. Tanumihardjo, PhD

    Professor
    University of Wisconsin-Madison
    Madison, Wisconsin, United States

Objectives: This study aims to determine the viability and accuracy of inexpensive equipment to perform dose-response tests. Dose-response tests provide more accurate reflections of total body vitamin A (VA) stores, but current applications require trained staff and costly equipment for use in field settings. Objective 1 was to determine the stability of VA dosing capsules over time at different temperature and lighting conditions to guide storage recommendations. Objective 2 was to compare the accuracy of VA dose delivery using inexpensive, single-use syringes compared to a positive-displacement pipette as the reference standard.

Methods: Vitamin A stock was prepared in soybean oil and 200 µL was pipetted into capsules. Capsules were stored in 5 conditions: -20 °C, 4°C, room temperature (RT) dark, RT light, and 37°C. Vitamin A concentration was determined at baseline and over 16 months using UV-Vis spectroscopy (n=3 per condition*time). Three positive-displacement pipettes were used to determine target mass (reference standard) of 200 µL of soybean oil calibrated using water and adjusted for temperature and pressure. One technician tested eight disposable syringes in triplicate with 200 µL of soybean oil weighed to the nearest .0001g and reported as percent of target mass.

Results: Time, temperature, and light all influenced degradation. Storage at 37°C dropped below 95% stability at 3 weeks; 4°C had 97% stability at 3 months which reduced to 93% at 11 months; -20°C had 100% stability at 11 months but degraded by 16 months. RT light dropped below 95% stability at 4.5 weeks after baseline and RT dark dropped below 95% stability at 7 weeks. Syringes delivered an average (95% CI) percent of target mass of 101.4% (99.2, 103.6).

Conclusions: Vitamin A displayed higher rates of degradation in heat and light. VA in capsules stored at -20°C was stable for 11 months. Single-use syringes were accurate when used by a single technician and merit a larger sample size to determine usability.

Funding Sources: Work was supported by NIH-R01, the International Atomic Energy Agency (IAEA), and the Cargill-Benevenga Research Stipend.