Abstract
Panvitan® powder for prescription (PP) administrated in combination with pemetrexed sodium hydrate (PEM) for the purposes of folic acid supplementation is significantly degraded by exposure to humidity or light. Hence, we investigated the influence of humidity and light on the color of the powder and concentration of folic acid in PP. We prepared samples by placing 1 g of PP into separate bags and stored them for 28 d under normal delivery conditions, intermediate humidity, high humidity, and light exposure. The amount of folic acid was quantified by high-performance liquid chromatography, where the percentage was calculated assuming the initial amount was 100％. Under normal delivery conditions (room temperature, 50％ RH, shielded light) and intermediate humidity conditions (25℃, 75％ RH, shielded light), no significant changes in appearance or folic acid content were observed. The sample stored under high humidity conditions (25℃, 91％ RH, shielded light) changed in color from yellow to brown. The decrease in folic acid content was time dependent, and decreased to 47.1％ after 28 d. Under light exposure (room temperature, 50％ RH, 5,000 lux, 0.56 W/m2), the yellow color of PP becomes thin with time, while the folic acid content decreased to 73.2％ after 28 d. The amount of folic acid may have decreased without any concomitant visible changes in the powder. The results of this study are expected to facilitate the management of adverse effects of PEM.
