Comparison of Excretion of Nicotinuric Acid After Ingestion of Two Controlled Release Nicotinic Acid Preparations in Man

Abstract

We tested an inexpensive controlled-release nicotinic acid product (Bronson Pharmaceuticals, LaCanada, CA) and compared it with the standard, more expensive, controlled release product, Nicobid (Rorer Pharmaceuticals), by measuring the 24 hour urinary recovery of nicotinic and nicotinuric acids from ten subjects following 500 mg oral ingestion of each product. Nicotinuric acid is the major detoxification product of nicotinic acid and may serve as a simple quantitative index of hepatic biotransformation of nicotinic acid. Although both products demonstrated controlled release profiles, the rate of appearance of nicotinic and nicotinuric acid in the urine as well as the rate of in vitro drug dissolution of the Bronson product were more rapid compared with Nicobid. Moreover, the total amounts of nicotinic acid and nicotinuric acid recovered in the urine after 24 hours were greater for the Bronson product (P less than .05). Since sustained presentation of nicotinic acid to the liver may correlate with clinical antihyperlipidemic effects, our results suggest that the Bronson product may prove to be a clinically useful preparation.

Treatment of Hypercholesterolemia: Comparison of Younger versus Older Patients Using Wax‐Matrix Sustained‐Release Niacin

“…Sustained‐release formulations of niacin have been developed to reduce the incidence of side effects, but unfortunately some products seem to accomplish this by reduced absorption and bioavailability. Wax‐matrix niacin has been shown to have equivalent bioavailability on a milligram for milligram basis to unmodified niacin 5 . The results described in this paper can and should be attributed only to the wax‐matrix form of sustained release niacin (Endur‐acin) that is the only form of niacin with this type of sustained release delivery system.…”

“…Bioavailability Other studies have not specifically looked at response differences to niacin by age, but response differences by formulation (sustained‐release versus unmodified niacin) have been described 16 . It is apparent that there are wide differences in bioavailability, side effects, and lipid responses to the various formulations of niacin 5 , 6 , 23 . Sustained‐release formulations of niacin have been developed to reduce the incidence of side effects, but unfortunately some products seem to accomplish this by reduced absorption and bioavailability.…”

“…The bioavailability of the wax‐matrix form of sustained release niacin has been shown to be superior to a commonly prescribed capsule form of time‐release niacin 5 . An uncontrolled study using wax‐matrix niacin reported good efficacy and a relatively low incidence of medication dropouts (4%) and side effects 6 .…”

The bioavailability of sustained release nicotinic acid formulations.

“…The absorption of unchanged nicotinic acid from sustained-release formulations has been poorly characterized. Some of the early studies used nonspecific analytic methods, and in some bioavailability studies aspirin had been given prior to nicotinic acid in order to minimize flushing (Figge et al, 1988). Aspirin, however, greatly impairs the conjugation of nicotinic acid to nicotinuric acid (Ding et al, 1989) causing an increase in the bioavailability of nicotinic acid.…”

“…Concentrations of nicotinic acid and nicotinuric acid were measured using modifications of reported h.p.l.c. methods for serum (Hengen et al, 1978) and urine (Figge et al, 1988). To 0.5 ml of serum 0.05 ml distilled water and 3 ml acetone were added.…”