Plasma Levels of Nicotinic Acid Compounds in Niceritrol ^*‐Treated Rabbits

Abstract

Some pharmacokinetic properties of nicotinic acid (NA) and niceritrol (pentaerythritoltetranicotinate) were investigated in rabbits. Niceritrol released NA at a faster rate on incubation in vitro with plasma or liver homogenate than in a pure buffer solution, indicating that niceritrol was actively hydrolyzed. After administration of niceritrol to rabbits no niceritrol was present in the plasma but metabolites, probably lower esters of niceritrol, free NA and nicotinamide were found. On oral administration of NA in a dose of 16 mg/kg higher maximal plasma levels of free NA (~6 μg/ml) were noted than after adminstration of niceritrol (1.4 μg/ml) in the same dose. A diet producing hyperlipaemia and containing 0.5% niceritrol elevated the levels of free NA in the plasma by about 2 μg/ml. It also reduced the increase in plasma cholesterol. The investigation suggests that the pharmacological and pharmacokinetic properties of niceritrol in the rabbit are similar to those in man.