PT  - JOURNAL ARTICLE
AU  - Hong, Wen-Hal
AU  - Szulczewski, Dale H.
TI  - Stability of Vidarabine-5′-Phosphate in Aqueous Solutions
DP  - 1984 Mar 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 60--64
VI  - 38
IP  - 2
4099  - http://journal.pda.org/content/38/2/60.short
4100  - http://journal.pda.org/content/38/2/60.full
SO  - PDA J Pharm Sci Technol1984 Mar 01; 38
AB  - The hydrolysis kinetics of a new antiviral agent, vidarabine-5'-phosphate, was studied spec-trophotometrically at pH 4-10, μ = 0.5, at 99 °C. Vidarabine-5′-phosphate hydrolyses via water attack on the protonated, neutral, and mono-ionized species. The hydrolysis rates follow pseudo first-order kinetics. The pH-rate profile suggests that vidarabine-5′ phosphate attains its optimal stability in the pH region 9-9.5. The stability of vidarabine-5′ -phosphate at pH 6.85 was studied at 61°, 80°, and 99 °C. The Arrhenius activation energy found was 29.4 Kcal/mole, and the time required for 10% loss, to 9, was estimated from the Arrhenius plot (12.4 years at 25 °C).