Inositol nicotinate

Absorption

Gastrointestinal absorption of inositol hexanicotinate varies widely, with an average of 70% of an orally ingested dose absorbed from stomach and upper small intestines into the bloodstream as intact form. The maximum serum levels of nicotinic acid is reached approximately 6-10 hours after oral ingestion. At low concentrations, the absorption of nicotinic acid and nicotinamide is mediated by sodium ion-dependent facilitated diffusion. At higher concentrations, passive diffusion predominates with doses of 3 to 4 g of niacin being almost completely absorbed .

Toxicity

NOAEL is 4000mg. Inositol nicotinate can cause muscle pain, headache, redness of face, nausea, vomiting, edema and rash.

Originator

Hexanicotol,Philadelphia,US,1962

The Uses of Inositol nicotinate

myo-Inositol Hexanicotinate is an nicotinate conjugate of myo-inositol, an structural basis for a number of secondary messengers.

The Uses of Inositol nicotinate

benzidine substitute

What are the applications of Application

myo-Inositol hexanicotinate is a nicotinate conjugate of myo-inositol

Background

Inositol nicotinate, also known as Inositol hexaniacinate/hexanicotinate or "no-flush niacin", is a niacin ester and vasodilator. It is used in food supplements as a source of niacin (vitamin B3), where hydrolysis of 1 g (1.23 mmol) inositol hexanicotinate yields 0.91 g nicotinic acid and 0.22 g inositol. Niacin exists in different forms including nicotinic acid, nicotinamide and other derivatives such as inositol nicotinate. It is associated with reduced flushing compared to other vasodilators by being broken down into the metabolites and inositol at a slower rate. Nicotinic acid plays an essential role in many important metabolic processes and has been used as lipid-lowering agent. Inositol nicotinate is prescribed in Europe under the name Hexopal as a symptomatic treatment for severe intermittent claudication and Raynaud’s phenomenon.

Indications

Indicated as a dietary supplement for the source of niacin. Has been investigated for potential beneficial effects on serum lipids. In Europe, inositol hexanicotinate is indicated as a patented drug known as Hexopal, which is therapeutically indicated for the symptomatic relief of severe intermittent claudication and Raynaud’s phenomenon.

Definition

ChEBI: Inositol hexanicotinate is an inositol nicotinate. It is functionally related to a nicotinic acid.

Manufacturing Process

100 g of nicotinic acid were suspended in 265 ml of distilled and dried pyridine without stirring. 68 g of phosphorus oxychloride were added dropwise to this mixture under continual stirring. The temperature of the reactants, initially at 20°C, was allowed to rise to about 60°C, and this temperature was maintained for a further 60 minutes. Thereafter 24.5 g of meso-inositol wereadded gradually, the temperature being controlled so that it did not exceed about 80°C. The reactants were maintained at this temperature for from 2 to 3 hours, and thereafter the reaction mixture was poured into 500 ml of water. The pyridine salts formed during the reaction readily dissolved, and the mesoinositol hexanicotinate which had formed crystallized out. The ester was filtered off and washed with water and acetone or alcohol. Finally, the mesoinositol hexanicotinate was dried at 100°C.
The yield was 90%, the melting point of the product was 258°C to 260°C. and the chlorine content <0.01%.

brand name

Hexopal (Sterling Winthrop); Linodil (Sterling Winthrop); Palohex (Sterling Winthrop).

Therapeutic Function

Vasodilator

Pharmacokinetics

Inositol nicotinate mediates a vasodilatory, lipid-lowering and fibrinolytic effect on the cardiovascular system. Like other niacins, inositol nicotinate is a lipid-regulating agent that reduces the levels of plasma triglycerides, atherogenic apolipoprotein B (apoB)-containing lipoproteins (VLDL, LDL and lipoprotein a) while increasing antiatherogenic apoA-I-containing HDL levels .

Clinical Use

Peripheral vascular disease

Hyperlipidaemia

Drug interactions

Potentially hazardous interactions with other drugs
Statins: increased risk of myopathy.

Metabolism

Inositol nicotinate is believed to be slowly hydrolysed to nicotinic acid. The main route of metabolism is then conversion to N-methylnicotinamide and the 2-pyridone and 4-pyridone derivatives; nicotinuric acid is also formed.
Small amounts of nicotinic acid are excreted unchanged in urine.

Metabolism

Inositol nicotinate undergoes hydrolysis by plasma esterases, releasing free nicotinic acid and inositol in a sustained manner. The process takes more than 48hours, where the bloodstream enzymatic hydrolysis of inositol hexanicotinate was found to be slower in the first ester linkage of inositol hexanicotinate than in subsequent linkages . Sequential hydrolytic steps of inositol nicotinate forms one nicotinic acid molecule in each step, producing eventually six molecules of nicotinic acid and one inositol moiety .