A clinical evaluation to determine the safety, pharmacokinetics and pharmacodynamics of an inositol‐stabilized arginine silicate dietary supplement in healthy adult males. (LB418)

The purpose of this study was to characterize the PK/PD of Nitrosigine™, an inositol‐stabilized arginine silicate dietary supplement. Ten healthy males, 26.7 ± 5.4 years, took Nitrosigine™ qd for 14 days and attended test visits on Days 1 and 14. Fasting blood and saliva collections were performed pre‐dose and at 0.5, 1, 1.5, 2, 3, 4, 5 and 6 hours post‐dose for plasma arginine, serum silicon and salivary nitric oxide + nitrite (NO). After Day 1 dose, arginine levels increased (p<0.01) at 0.5, 1, 1.5, 2, 3 and 5 hours and silicon levels increased (p<0.05) at 1 and 1.5 hours. Day 1 PK parameters for arginine were: CMax 27.25±4.86 µg/ml and tMax 1.05±0.50 and for silicon: CMax 2.77±0.74 µg/ml and tMax 2.15±1.75. After Day 14 dose, arginine levels increased (p<0.05) at 0.5, 1, and 1.5 hours, and silicon levels increased (p<0.01) at 1, 1.5, 2, and 3 hours. After 14 days of use, baseline arginine trended towards being higher than baseline Day 1 (p=0.0645), and 4‐hour post‐dose plasma arginine was significantly higher (p=0.0488). Although not a significant difference, NO increased in four subjects and stayed the same in six subjects at 0.5 hours after the first dose (p=0.125). After 14 days of use, baseline NO levels increased in six subjects and stayed the same in four subjects (p=0.031). No safety concerns were raised by this study.