Solubility niacinamide

Description of Method. The water-soluble vitamins Bi (thiamine hydrochloride), B2 (riboflavin), B3 (niacinamide), and Be (pyridoxine hydrochloride) may be determined by CZE using a pH 9 sodium tetraborate/sodlum dIhydrogen phosphate buffer or by MEKC using the same buffer with the addition of sodium dodecyl-sulfate. Detection Is by UV absorption at 200 nm. An Internal standard of o-ethoxybenzamide Is used to standardize the method. 

The SP procedure of water-soluble vitamins from multivitamin tablets is particularly challenging due to the diverse analytes of varied hydrophobicities and pfC. Water-soluble vitamins (WSVs) include ascorbic acid (vitamin C), niacin, niacinamide, pyridoxine (vitamin B ), thiamine (vitamin Bj), folic acid, riboflavin (vitamin B2) and others. While most WSVs are highly water soluble, riboflavin is quite hydrophobic and insoluble in water. Folic acid is acidic while pyridoxine and thiamine are basic. In addition, ascorbic acid is light sensitive and easily oxidized. The extraction strategy employed was a two-step approach using mixed solvents of different polarity and acidity as follows ... 

The water-soluble vitamins niacinamide (a neutral compound), riboflavin (a neutral compound), niacin (an anion), and thiamine (a cation) were separated by micellar electrokinetic chromatography in 15 mM borate buffer (pH 8.0) with 50 mM sodium dodecyl sulfate. The migration times were niacinamide (8.1 min), riboflavin (13.0 min), niacin (14.3 min), and thiamine (21.9 min). What would the order have been in the absence of sodium dodecyl sulfate Which compound is most soluble in the micelles ... 

Niacinamide Ascorbate occurs as a yellow colored powder that may gradually darken upon exposure to air. It is a complex of ascorbic acid (CgHgOg) and niacinamide (CfiiySLO). One gram is soluble in 3.5 mL of water and in about 20 mL of alcohol. It is very slightly soluble in chloroform and in ether and is sparingly soluble in glycerin. 

Estradurin Injection (Polyestradiol phosphate, Wyeth-Ayerst Labs) uses Niacinamide (12.5 mg/ ml) as a solubilizing agent. Hydeltrasol also contains niacinamide. The concept of hydrotropic agents to increase water solubility has been tried on several compounds, including proteins. " " " ... 

Niacinamide, U5P. Niacinamide, nicotinamide, nicotinic acid amide, is prepared by the amidation of esters of nicotinic acid or by pa.ssing ammonia gas into nicotinic acid at 320°C. Nicotinamide is a white cry.stalline powder that is odorless, or nearly so, and bitter. One gram is soluble in about I mL of water, I.S mL of alcohol, and about 10 mL of glycerin. Aqueous solutions aie neutral to litmus. For occurrence, action, and uses, see nicotinic acid. Niacinamide has pK values of O.. and 3.35. 

Over 40 kinds of alkaloids from tobacco have been isolated and identified. The major alkaloids from tobacco are nicotine, cotinine, nornicotine, myosmine, nicotyrine, anabasine, and anatabine. The nicotine content is highest of most of the alkaloids and nicotine (Figure 8.3) has insecticidal, detoxifying, and refreshing activities. Nicotine is also commonly used to synthesize niacin and niacinamide (key intermediates). Niacinamide (Figure 8.3) is the amide of nicotinic acid (vitamin B3/niacin), a water-soluble... 

Most media contain water-soluble B vitamins. Common to many formulations are vitamins Bi (thiamine), B2 (riboflavin), B3 (niacinamide), Bj (pantothenic acid). Be (pyridoxine), and Bg (folic acid). Biotin (vitamin H), cyanocobalamin (vitamin B]2 ), and ascorbic acid (vitamin C) are also common vitamin components. Although choline and inositol are classically grouped with vitamin components, in cell culture they function as metabolic substrates rather than as catalysts. 

In a wonderfully short and effective separation, seven water-soluble vitamins (ascorbic acid, niacin, niacinamide, pyridoxine, folic acid, thiamine, riboflavin) were baseline resolved on a Cg column using an isocratic 7/93 acetonitrile/water (1% acetic acid and 5mM sodium heptanesulfonate) mobile phase [1114]. Elution was complete in 6 min. 

Niacin, also known as vitamin B3, nicotinic acid or vitamin PP, is a water-soluble B-complex vitamin (Table 7.1). This vitamin is the generic descriptor for two vitamers niacin and niacinamide. In the research literature the terms nicotinic acid/nicotinamide are most commonly used, while in medical practice niacin/niadnamide are preferred. The vitamin is obtained from the diet in the form of nicotinic acid, nicotinamide and tryptophan, which are transformed to nicotinamide adenine dinucleotides, NAD and NADP. These compounds participate in cellular oxidation-reduction reactions that are critical for energy production. NAD and NADP also participate in a wide variety of... 

Multivitamin preparations. Most water-soluble vitamins are polarographically active and can be determined in simple preparations without any difficulties. Difficulty is given, however, with complex multivitamin preparations. In a preparation containing in I O g (in addition to fillers) 2500 I.U. of vitamin A, 200 I.U. of vitamin D, 1 mg of vitamin Bj, T5 mg of vitamin Bg, 1 /ag of vitamin B 2> mg of pteroylglutamic acid, 0-5 mg of calcium pantothenate, 10 mg of niacinamide, 37-5 mg of vitamin C, 1 mg of vitamins E and 0-2 mg of vitamins K, the analyses were carried... 

Riboflavin is an ingredient of many pharmaceutical multivitamin preparations. Methods have been described for the determination of riboflavin and other, water-soluble vitamins (Bj, B, B12, niacin, niacinamide, folic acid, ascorbic acid). For... 

Figure 9 Effect of water/methanol ratio with tetrabutylammonium phosphate reagent on retention times of water-soluble vitamins on xBondapak C18 ascorbic acid (O), niacin ( ), folic acid ( ), pyridoxin ( ), riboflavin (A), vitamin Bjj (A), niacinamide (V), thiamine (V), x not eluted from column. (From Ref. 103.)... 

Some rationalization of drug complexation is possible by the use of Hiickel frontier molecular orbitals [300]. These confirm 7i-donor-7c-acceptor mechanisms for the interactions with niacinamide of the compounds shown below in aqueous solution. Phase-solubility diagrams all showed positive deviations from linearity, behaviour attributed to first- and second-order interactions between the solute (S) and the hydrotrope (H) ... 

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