Pharmacokinetics of a Novel Sustained-Release Vitamin C Oral Tablet: A Single Dose, Randomized, Double-Blind, Placebo-Controlled Trial

Objectives: To evaluate the pharmacokinetics of a novel sustained-release oral tablet (C-Fence, Inventia Healthcare Limited, Mumbai, India).

Methods: We conducted a randomized, placebo-controlled, parallel-design, 500 mg single-dose pharmacokinetic study of this new preparation in 18 healthy adult human subjects (nine in each group) under fasting conditions. The concentration-time profile and pharmacokinetic parameters of L-ascorbic acid, including Cmax (maximum plasma concentration), Tmax (time to reach Cmax), and AUC0-24h (area under the plasma concentration versus time curve from time 0 h to 24 h) were calculated using baseline-corrected values.

Results: The sustained-release tablets resulted in mean Cmax and AUC0-24h, respectively, of 1.39 ± 1.21 μg/mL and 11.72 ± 10.73 μg.h/mL against 0.18 ± 0.10 μg/mL and 0.89 ± 0.27 μg.h/mL, respectively, in the placebo group. The mean Tmax with the sustained-release tablets was 4.3 ± 2.5 h. At 12, 16, and 24 h from dosing, the concentrations were 0.6, 0.4, and 0.3 μg/mL, respectively, above baseline values.

Conclusion: Novel sustained-release formulations of vitamin C are expected to help achieve plasma vitamin C values above the homeostatic saturation level and result in higher steady-state plasma concentration, which might result in better cellular uptake.