Water-soluble vitamin tablets

Assay of Water-soluble Vitamins (WSVs) in Multivitamin Tablets... 

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 ... 

FIGURE 7 HPLC chromatogram of water-soluble vitamin in multivitamin tablets. See Reference 33 for details. Reprinted with permission from Reference 33. 

Water-soluble vitamins in formulations have been determined by use of ion-pair chromatography. The vitamins include several B vitamins as well as niacin, folic acid, and ascorbic acid (565). Vitamins D and Da were rapidly separated on reverse phase columns (247) as are vitamins A, D, and E in multivitamin tablets (564). Addition of silver ions to the mobile phase has been shown to increase the flexibility inherent in RPC by complexing with the unsaturated bonds and thereby decreasing the retention factor. This effect is also observed with other unsaturated drug molecules including steroids (247). Vitamin A and related compounds have... 

A large number of methods have been developed for analysis of water-soluble vitamins simultaneously in pharmaceutical products (like multivitamin tablet supplements). In fact, for these products no particular sample preparations are required and the high concentrations simplify the detection, enabling the use of UV [636]. The use of MS is also reported [637]. As well, Moreno and Salvado [638] reports also the use of a unique SPE cartridge (C18) for separating fat-soluble and water-soluble vitamins, which are, then analyzed using different chromatographic systems. 

Reversed micelles can be used to concentrate water-soluble materials in the water pool of SCCO2. The extraction of water-soluble vitamins into reversed micelles has been examined. The efficiency of extraction was strongly affected by the extraction temperature and the concentration of reversed micelles, and the selectivity depended on the size of micelles. Water-soluble vitamins could be efficiently and rapidly extracted. The selective extraction of a model mixture of vitamins from pharmaceutical preparations was also demonstrated. Moreover, the usefulness of the proposed method for the determination of vitamins in various commercial tablets was also demonstrated. Using this method, the surfactant remains mixed with the extracted com-... 

The application of SCF to the extraction of vitamins has been widely reported. Thus, retinyl palmitate and tocopherol acetate have been extracted from a hydrophobic ointment with supercritical CO2 at 40°C and 196 bar for 4 min, the extract analysis being performed by SFC (137). The calibration graphs were linear from 0.5 to 2.5 pg and the recoveries were quantitative. On the other hand, water-soluble vitamins can be extracted mixing them with low substituted hydroxypropil cellulose. Portions were placed in a column to which a reversed micellar extractant was delivered (138). Extraction of vitamins A and E and their esters from tablet preparations prior to FIPLC was performed in the dynamic mode with CO2 at 40°C and 253 bar for 15 min (139). Calibration graphs were linear from 0.02 to 0.8 and from 0.005 to 0.2 mg/mL of vitamins E and A, respectively. The corresponding RSDs (six... 

Figure 6.5. HPLC chromatograms showing the analysis of water-soluble vitamins in multivitamin capsules tablets. Reprinted with permission from reference 17.

The water-soluble vitamins are organic substances needed in small amoimts in the diet because they are required for a variety of essential enz)unatic reactions in cells. The water-soluble vitamins are components of many coenz)unes that are required by enz)unes to carry out a variety of important biochemical reactions. Once ingested, these vitamins undergo chemical modifications that convert them into coenz)unes. However, it serves no purpose to consume vast quantities of water-soluble vitamins by taking enormous doses of vitamin tablets because they are not stored in the body. Because they are soluble in water, the excess is simply excreted in the urine. Table 20.1 lists the coenz)unes derived from the water-soluble vitamins and their chemical functions. Table F.l provides the major nutritional sources of the water-soluble vitamins and the clinical conditions that result from their deficiency. 

Vitamin B12 (cobalamine) is needed to metabolize fatty adds and amino acids and to synthesize DNA in cells. Vitamin C also has several functions. It is needed to synthesize collagen, the most abundant protein in the body, but it also acts as an antioxidant, helping to reduce the risk of developing chronic diseases like heart disease and cancer. Water-soluble vitamins are not stored in the body. Because they are eliminated in urine, a continuous daily support through diet is required. However, even foods that contain the necessary vitamins can have reduced vitamin content after storage, processing, or cooking. Therefore, many people take a multivitamin tablet to supplement their diet. To ensure that these tablets contain the labeled amounts of vitamins, there must be a quality control assay for these tablets. 

Su, S.C., Chou, S.S., Hwang, D.F., Chang, P.C., and Liu, C.H., 2001. Capillary zone electrophoresis and micellar electrokinetic capillary chromatography for determining water-soluble vitamins in commercial capsules and tablets. Journal of Food Science. 66 10-14. 

Chen, P., Chen, B., and Yao S., 2006. High-performance liquid chromato-graphy/electrospray ionization-mass spectrometry for simultaneous determination of taurine and 10 water-soluble vitamins in multivitamin tablets. Analytica Chimica Acta. 569 169-175. 

Chen, P., Atkinson, R., and Wolf, W.R., 2009. Single-laboratory validation of a high-performance liquid chromatographic-diode array detector-fluorescence detector/mass spectrometric method for simultaneous determination of water-soluble vitamins in multivitamin dietary tablets. Journal of AOAC... 

Bican-Fister, T., and Drazin, V. (1973). Quantitative analysis of water-soluble vitamins in multicomponent pharmaceutical forms. Determination of tablets and granules. J. Chromatogr. 77 389-395. 

The simultaneous determination of the B vitamins, thiamine, riboflavin, pyridoxal, pyridoxine, and pyridoxamine in a pharmaceutical product using CZE was described by Huopalahti and Sunell (90). Hydrochlorid acid was used for the extraction of the vitamins from the multivitamin-multimineral tablet. The applied potential was 6.0 kV, and a 75-p.m fused-silica capillary tubing was used. The electrolyte used was a 20-mM sodium phosphate buffer pH 9.0. A clear separation of standards as well as of the pharmaceutical sample is shown in Figure 14. This method appears to be a fast and simple technique for the simultaneous determination of water-soluble vitamins in pharmaceutical products, where the... 

Pantothenic acid/calcium pantothenate in pharmaceutical products and vitamin premixes was also analyzed using low-wavelength ultraviolet (UV) detection (64,66). The vitamin was extracted from tablets or powdered premixes with 0.005 M NaH2P04 buffer (pH 4.5) and separated from other water-soluble vitamins on an aminopropyl-bonded silica column (LiChrosorb NH2) eluted with an acetonitrile-0.005 MNaH2P04 buffer (pH 4.5) (87 13, v/v) and detected at 210 nm. Quantitative recoveries (>95%) and relative standard deviations 0.79% to 2.2% were obtained for multivitamin tablets, vitamin premixes, fortified yeasts, and raw materials. The limit of sensitivity was approximately 1 mg/g sample. The results were compared with those obtained by the standard microbiological procedure. Low levels of calcium pantothenate (<3 mg per tablet) were more precisely analyzed by the HPLC procedure than by the microbiological method. 

Magnesium (jiuconate. CAS 3632-9l-5 MgtCV.U,(), ). 211-0. white powder ot line needles, odorless, almost tasteless, soluble in water, combustible, formed hy reaction of magnesia or magnesium carbonate dissolved in gluconic acid. Uses Medicine, and vitamin tablets. 

Liquid-liquid extraction is generally reserved for more complex samples because it offers poorer precision than other techniques. It is most commonly used for the preparation of biological samples in which less precise methods can be tolerated. Occasionally, however, an extraction is necessary for the determination of a water-insoluble compound in a water-soluble matrix, such as the analysis of fat-soluble vitamins in tablets or menthol in pharmaceutical lozenges. In these cases, the water-soluble matrix must be treated with water to gain access to the analytes, but the solvent cannot be made sufficiently nonpolar to dissolve the analytes by adding a water-miscible solvent. 

Water-soluble CdTe nanorods modified with thioglycolic acid and cysteine have been used as a fluorescence probe for the determination of vitamin Bi (Li et al. 2010). The size-dependent luminescence of the nanorods was studied in this work. A synthesized nanorod of short length was not luminous, even in the presence of vitamin Bi, but longer nanorods emitted strong light at a wavelength of 665 nm in the presence of vitamin Bi. The degree of enhancement of the luminescence intensity was proportional to the concentration of vitamin Bi. The LOD was achieved at micromolar scale. The method was applied to determine vitamin Bi in a commercial tablet and vitamin B complex. 

A tasteless, odorless, water soluble salt of calcium. It may be administered intravenously for the relief of tetany, caused by an abnormal decrease in blood serum calcium and characterized by cramplike involuntary muscle spasm. Also, calcium gluconate is used as a food additive, buffer, and firming agent, and in some vitamin tablets. 

Tribasic calcium phosphate is soluble in dilute mineral aeids, very slightly soluble in water, and insoluble in aleohol. It is used in the pharmaceutical industry primarily as a tablet and eapsule diluent and as a flow and non-caking agent. Tribasic calcium phosphate provides a higher calcium load than dibasic calcium phosphate. It should not be used with strong acidie salts of weak organic bases or in the presenee of acetate salts. It influences the adsorption of vitamin D, and should not be used with water soluble B vitamins or with certain esters sueh as vitamin E or vitamin A acetate or palmitate. It forms a ealeium eomplex with tetracycline. A tablet formulation utilizing triealeium phosphate as a filler is shown below. 

Menadiol Sodium Diphosphate, USP. Menadiol sodium diphosphate, letrastxlium 2-methyl-1.4-nuphthalene-diol bis(dihydrogen phosphate), tetrasodium 2-mcthylnuph-thohydroquinone diphosphate, vitamin K4. is a white hygroscopic powder, very soluble in water, giving solutions with a pH of 7 to 9. It is available in ampuls for use subcutaneously, intramuscularly, or intravenously and in tablets for oral administration. Unlike the other vitamin K analogues, menadiol oral absorption does not depend on the presence of bile. Once absorbed, it is converted to inenadione. 

Hygroscopic, dark red crystals. When exposed to air, may absorb about 12% water. The hydrated crystals are stable to air. Darkens at 210-220 . Not melted at 300 . [a] — 59 9" (dil aq soln). Absorption max (water) 278, 361. 550 nm (A12, 115. 204, 64). Odorless and tasteless. One gram dissolves in about 80 ml water. Aq solns are neutral, maximum stability in the pH range 4.5-5. Solns in this pH range can be autoclaved for 20 min at 120 . Soluble in ale. Insol In acetone, CHCl3, ether. Aq solns decomp in the presence of acacia, aldehydes, ascorbic acid, ferrous gluconate, ferrous sulfate, vanillin are stabilized hy the addn of ammonium sulfate. Talc has a tenacious affinity for vitamin B1t although this is not an incompatibility, it precludes the use of talc as a filter aid or lubricant for tablets, particularly in view of possible assay difficulties. 

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